US3915715A - Silver halide photographic materials containing a high weight ratio of gold to sulfur sensitizers and a sensitizing methine dye - Google Patents

Abstract

Light-sensitive silver halide grains having an average size of up to .2 micron are sensitized with a noble metal sensitizer at a concentration of at least 50 mg. noble metal per mole of silver, and a sulfur sensitizer at a weight ratio of sulfur to noble metal of about 1:15 to 1:75; said silver halide grains being spectrally sensitized with a photographic spectral sensitizing methine dye.

Description

United States Patent Millikan et al.

[ *Oct. 28, 1975 Inventors: Allan G. Millikan, Webster; Mary Jane W. Brizee, Pittsford, both of N.Y.

Eastman Kodak Company, Rochester, N.Y.

Assignee:

Notice: The portion of the term of this patent subsequent to Aug. 13, 1989, has been disclaimed.

Filed: May 16, 1973 Appl. No.: 360,719

Published under the Trial Voluntary Protest Program on January 28, 1975 as document nov B 360,719.

Related US. Application Data Continuation-in-part of Ser. No. 63,606, Aug. 13, 1970, Pat. No. 3,753,721.

US. Cl. 96/123; 96/108; 96/127; 96/128; 96/133; 96/140; 260/2401 [51] Int. Cl. G03C l/10 [58] Field of Search 96/127, 108, 123, 128, 96/140 [56] References Cited UNITED STATES PATENTS 3,558,614 1/1971 Jenkins 96/127 3,565,630 2/1971 Millikan et al.... 96/123 3,695,888 10/1972 Hiller et a1 96/127 3,736,141 5/1973 Overman et al. 96/108 3,743,510 7/1973 Nakazawa et al.... 96/127 3,753,721 8/1973 Millikan et al 96/127 Primary Examiner-J. Travis Brown Attorney, Agent, or FirmM. R. Chipaloski [57] ABSTRACT Light-sensitive silver halide grains having an average size of up to .2 micron are sensitized with a noble metal sensitizer at a concentration of at least 50 mg. noble metal per mole of silver, and a sulfur sensitizer at a weight ratio of sulfur to noble metal of about 1:15 to 1:75; said silver halide grains being spectrally sensitized with a photographic spectral sensitizing methine dye.

9 Claims, N0 Drawings SllLVlER HALTDE PHOTOGRAPHIC MATERIALS QGNTATNING A HIGH WEIGHT RATIO OF GOLD TU SULFUR SENSITIZERS AND A SENSllTIZING METHINE DYE This is a continuation-in-part of my copending U.S. application Ser. No. 63,606 filed Aug. 13, 1970, now U.S. Pat. No. 3,753,721.

This invention relates to photographic materials, and more particularly to fine grain silver halide photographic materials.

The combination of noble metal sensitizers and sulfur sensitizers has been suggested in the prior art for photographic silver halide emulsions. Typical disclosures of such sensitizers are made by Smith et al in U.S. Pat. No. 2,448,060 issued Aug. 31, 1948, Baldsiefen U.S. Pat. No. 2,540,085 issued Feb. 6, 1951; Damschroder U.S. Pat. No. 2,597,856 issued May 27, 1952 and Damschroder et a1 U.S. Pat. No. 2,642,361 issued June 16, 1953. Hiller in U.S. Pat. application Ser. No. 757,789 filed Sept. 5, 1968, now U.S. Pat. No. 3,753,920 and corresponding Belgian Pat. No. 724,740 of Dec. 31,-

1969, describes spectrally sensitized fine grain silver halide emulsions and states that such emulsions can be sensitized with sulfur and gold sensitizers. However, none of these references, nor any other references known to applicants, suggest the sensitization of fine grain silver halide emulsions with a high concentration of noble metal sensitizer together with a low concentration of sulfur sensitizer.

Previously, it had been assumed that noble metal senstization was most effective with large silver halide grains. Glafkides, Photographic Chemistry, published by the Fountain Press, London, 1958, states at page 320 that gold sensitization is mainly effective with large silver halide grains, which have higher sensitivity to light than fine silver halide grains (i.e., up to .2 micron in size). Glafkides also states at page 319 that gold sensitization frequently results in substantial increases in fog and causes emulsion instability, which often results in the emulsion becoming useless after being kept for a few days.

Fine grain silver halide emulsions must be used instead of faster large grain silver halide emulsions for various purposes, for example in photographic applications where high resolution is essential, such as holography and microphotography. Hence, it appears highly desirable to provide stable emulsions comprising fine silver halide grains which have low fog and high speeds.

One object of this invention is to provide photographic silver halide grains which exhibit increased speed to blue radiation.

Another object of this invention is to provide chemically sensitized photographic silver halide emulsions which are stable and exhibit increased speed to blue radiation.

A further object of this invention is to provide photographic silver halide emulsions which are particularly useful in applications requiring high resolving power, such as holography and microphotography.

Still another object of this invention is to provide spectrally sensitized photographic silver halide emulsions.

Another object of this invention is to provide spectrally sensitized fine grain silver halide emulsions having higher speeds in the region of spectral sensitivity.

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

In accordance with this invention, light-sensitive silver halide grains having an average grain size up to about .2 micron are sensitized with the combination of a noble metal sensitizer, at a concentration of about at least 50 milligrams noble metal per mole of silver, and a sulfur sensitizer at a weight ratio of sulfur to noble metal of about 1:15 to 1:75; and, the silver halide grains are spectrally sensitized with a photographic spectral sensitizing methine dye.

The combination of a high concentration of noble metal sensitizer and a low concentration of sulfur sensitizer, together with a photographic spectral sensitizing dye, results in substantial and unexpected speed increases in the region of inherent sensitivity of silver halide grains. The increase in inherent sensitivity is accomplished without causing high fog or emulsion instability.

Silver halide grains employed in the practice of this invention can comprise silver chloride, silver bromide, silver bromoiodide, silver chlorobromoiodide or mixtures thereof. The silver halide grains can range in size up to .2 micron, and preferably up to .15 or .1 pm. Grains in the range of about .02 up to .09 micron give excellent results. Such silver halide grains can be prepared by any of the well-known procedures. Very fine grain emulsions known in the art as Lippmann emulsions are useful herein.

The noble metal sensitizers useful in this invention include the well known gold sensitizers and other noble metals such as palladium and platinum, including any of the noble metal sensitizers described in Smith et a1 U.S. Pat. No. 2,448,060 issued Aug. 31, 1948. Typical useful gold sensitizers are described in Waller et al U.S. Pat. No. 2,399,083 issued Apr. 23, 1946, Baldsiefen U.S. Pat. Nos. 2,540,085 and 2,540,086 both issued Feb. 6, 1951; Damschroder U.S. Pat. No. 2,597,856 issued May 27, 1952 and Damschroder et a1 U.S. Pat. No. 2,642,361 issued June 16, 1953. Illustrative addenda suitable for furnishing the noble metal moiety in accordance with this invention include: gold chloride potassium aurate,

potassium auriaurite,

potassium auricyanide, potassium aurithiocyanate, gold sulfide, gold selenide, gold iodide, potassium chloroaurate, ethylenediamine-bis-gold chloride, ammonium chloroplatinate, i.e., (NH PtCl ammonium chloropalladate, i.e., (Nl-l PdCl and organic gold sensitizers having the formulas:

CH3 Allelull C-SAu t -SA \s C u The noble metal sensitizer is employed in accordance with the invention in a concentration of from at least about 50 milligrams of noble metal per mole of silver,-

and preferably from about to milligrams noble metal sensitizer per mole of silver. Note that concentrations of noble metal are expressed in terms of noble metal and are not based on the total weight of the compound containing the noble metal. The noble metal sensitizer is employed at concentrations lower than which causes substantial fog, such as fog levels over 3. Generally, there is no advantage in employing over 200 mg. noble metal per mole of silver.

in accordance with the invention, the silver halide grains are chemically sensitized with a sulfur sensitizer. Sulfur sensitizers are well known in the art and are described, for example, by Damschroder et al US. Pat. No. 2,642,361 issued June 16, 1953, columns 3 and 4. Typical sulfur sensitizers contain a =C=S group or a CSSC-- group. Typical sulfur sensitizers are thiourea, allylisothiocyanate, thiosinamine (allylthiourea), cystine and B-ethyl xanthate propionic acid. Also useful are methyl or ammonium thiocyanates, such as alkali metal thiocyanates (e.g., sodium or potassium thiocyanate) or alkaline earth metal thiocyanates (e. g., calcium thiocyanine, strontium thiocyanate, etc.), cadmium thiocyanate and ammonium thiocyanate. Especially useful are the alkali metal thiosulfates, preferably sodium or potassium thiosulfate, or ammonium thiosulfate. Thioureas, such as those referred to above, also produce particularly useful results.

Sulfur sensitizers are employed herein at a weight ratio of sulfur to noble metal of about 1:15 to 1:75, and preferably about 1:30 to about 1:50. The amount of labile sulfur, not the entire weight of the compound containing the labile sulfur, is used in calculating the useful concentrations of sulfur. As will be apparent to those skilled in the art, certain sulfur sensitizers (e.g., sodium thiosulfate) contain two sulfur atoms, but only one of those sulfur atoms is labile. These compounds are used in concentrations calculated on the basis of the one labile sulfur atom therein.

Any methine (including polymethine) photographic spectral sensitizing dye can be employed in the practice of this invention. Typical useful methine dyes have oxidation potentials (E or E of less than 0.90 volt and reduction potentials (E or E) more negative than minus 0.80 volt.

The electrochemical potential measurements of suitable methine dyes can be made with an approximately 10 molar solution of the dye in an electrolyte; for example, methanol which is 0.05 molar in lithium chloride. A dropping mercury electrode can be used for the cathodic measurement with the polarographic halfwave potential for the cathodic response most positive in potential designated E A pyrolytic graphite electrode can be used for the anodic response most negative in potential designated E In each measurement, the reference electrode can be an aqueous silver-silver chloride (saturated potassium chloride) electrode at 20 C. Plus and minus signs are assigned to the potential values according to the IUPAC Stockholm Convention 1953. The E and E values so measured shall not include processes in which electron transfer is primarily the result of the presence in solution of the counter ion of a positively charged dye or other such chemical entities in solution that are not an integral part of, or attached to, the chromophoric system of the dye. A response of lesser current magnitude preceding the primary response, such as a prewave resulting from adsorption of the electrolysis product to the electrode surface, shall be excluded from designation as E or E,..

Electrochemical measurements of this type are known in the art and are described in one or more of the following reference texts: New Instrumental Methods in Electrochemistrv, by Delahay, Interscience Publishers, New York, New York, 1954; Polarography, by Kolthoff and Lingane, 2nd Edition, Interscience Publishers, New York, New York, 1952; and Electrochemistry at Solid Electrodes, by Adams, Marcell Dekker, lnc., New York, New York, 1969.

The dyes can be used in widely varying concentrations, with optimum concentrations being determined by any suitable means previously described in the art. Generally, about 100 to 2,000 mg. dye per mole of silver provide good results, although larger or smaller amounts produce useful results depending on the particular dye and silver halide used.

Typical useful cyanine dyes have the following general formula:

X9 wherein d and n each represents a positive integer of from 1 to 2, m represents a positive integer of from 1 to 5, each L represents a methine group (e.g., CH=, C(CH etc.), and Z and Z each represents the non-metallic atoms necessary to complete a heterocyclic nucleus containing from five to six atoms, such as used in cyanine dyes, which nuclei can 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, 5- methylthiazole, S-phenylthiazole, 4,5-dimethylthiazole, 4,5-diphenylthiazole, 4-(2-thienyl)thiazole, benzothiazole, 4-chlorobenzothiazole, 5-chlorobenzothiazole,

6-chlorobenzothiazole 7-chlorobenzothiazole, 4- methylbenzothiazole, S-methylbenzothiazole, 6- methylbenzothiazole, 5 -bromobenzothiazole, 6-

bromobenzothiazole, S-phenylbenzothiazole, 6-phenylbenzothiazole, 4-methoxybenzothiazole, S-methoxybenzothiazole, 6-methoxybenzothiazole, 5-iodobenzothiazole, -iodobenzothiazole, 4-ethoxybenzothiazole, S-ethoxybenzothiazole, tetrahydrobenzothiazole, 5,-dimethoxybenzothiazole, 5,6-dioxymethylenebenzothiazole, 5-hydroxybenzothiazole, 6- hydroxybenzothiazole, naphtho[2,l-d]thiazole, naphtho[ l,2-d]thiazole, 5-methoxynaphtho[ 2,3-d]thiazole, 5-ethoxynaphtho[2,3-d]thiazo1e, S-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, S-methyloxazole, 4-phenyloxazole, 4,5-diphenyloxazole, 4- ethyloxazole, 4,5-dimethyloxazole, S-phenyloxazole, benzoxazole, S-chlorobenzoxazole, S-methylbenzoxazole, S-phenylbenzoxazole, 6-methylbenzoxazole, 5,6- dimethylbenzoxazole, 4,6-dimethylbenzoxazole, 5- methoxybenzoxazole, S-ethoxybenzoxazole, 5- chlorobenzoxazole, 6-methoxybenzoxazole, S-hydroxybenzoxazole, 6-hydroxybenzoxazole, naphtho[2,1- d]oxazole, naphtho[1,2-d]oxazole, etc.; a selenazole nucleus, e.g., 4-methylselenazole, 4-phenyl'elenazole,

line, etc.; a 3,3-dialkylindolenine nucleus, e.g., 3,3-

dimethylindolenine, 3,3,S-trimethylindolenine, etc.; and, an imidazole nucleus, e.g., imidazole, 1- alkylimidazole, 1-alkyl-4-phenylimidazole, 1-alkyl-4,5- dimethylimid azole, be nzimidazole 1 -alkylbenzimidazole, 1-aryl-5,6-dichlorobenzimidazole, 1 -alkyl- Ill-naphtho[ l,2-d]imidazole, l-aryl-3H-naphtho[ 1,2- d]imidazole, l-alkyl-S-methoxy- 1 H-naphtho[ 1,2- d]imidazole, etc.; X represents an acid anion, such as chloride, bromide, p-toluene sulfonate, methane sulfonate, methylsulfate, ethylsulfate, perchlorate, etc.; R and R each represents an alkyl group (including substituted alkyl) having from one to 18, and preferably one to four carbon atoms, such as methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, hexyl, dodecyl, octadecyl, benzyl, B-phenylethyl, sulfoalkyl such as /3sulfoethyl, 'y-sulfopropyl, 'y-sulfobutyl, fi-sulfobutyl, etc.; carboxyalkyl such as B-carboxyethyl, y-carboxypropyl, (E-carboxybutyl, etc.; sulfatoalkyl such as 'y-sulfatopropyl and S-sulfatobutyl, etc. It will be noted that in some instances, the acid anion, represented by X in the above formula, is included in the substituent represented by R such as dyes containing the betaine type structure. Some specific cyanine dyes that can be used in the process of this invention include the following: 1 ,3-diethylthia-2'-cyanine chloride 1,1 -diethyl-2,2 -cyanine chloride 3 3 '-diethyloxacarboc yanine iodide 5 ,5 '-dichloro-3,3 -diethylthiacarbocyanine iodide 1,1 '-diethyl-2,2-carbocyanine iodide 3 ,3 -diethylthiazolocarbocyanine iodide 3,3'-diethyl-4,4'-diphenylthiazolocarbocyanine iodide 3 ,3 '-diethyl-9-methylthiacarbocyanine iodide l ,3,3 -triethylbenzirnidazolo-oxacarbocyanine iodide 5-chloro-1 ,3 ,3 '-triethylbenzimidazolo-oxacarbocyanine iodide In another useful class of cyanine dyes are tricarbocyanine dyes in which the meso carbon atom of the methine linkage of the dye is attached to the nitrogen atom of an amino group which forms an enamine with the methine linkage of the tricarbocyanine dye. The term tricarbocyanine denotes dyes having the ammidinium-ion chromophoric system (see Mees and James, The Theory of the Photographic Process, Third Edition, 1966, page 201). Typically, such dyes have two nitrogen-containing heterocyclic nuclei which are joined by a straight chain methine linkage having seven methine groups. The carbon atom of the central methine group of the methine linkage is referred to herein as the meso carbon atom of the methine linkage.

The word enamine is used herein to refer to the See Advances Organic Methods and Results, VolurfiE i; Raphael; rayler and Wynberg, 1963,

7 8 Interscience, page 3, and Fieser and Fieser, Advanced T bl D c mi d Organic Chemistry, Reinhold Publishing Corp., 1961,

3 es 494 499 XVIII ll-Diethylamino-3,3-diethyl-l0,I2-ethylenethiatricarp g I bocyanine perchlorate The Preferred enamme trlcarbocyamne dyes used XIX ll-Diethylamino-lO,l2-ethylenel,1l,3,3,3',3'-hexameherein have the following formula: thylindotricarbocyanine perchlorate R5 R6 2 N z I z I/ 2 I 3 Q wherein a and b each represents an integer of from 1 to xx 3,3'-D iethyll0,l2-ethylene-l l-[ l I ,2,3 4-tetrah 2;X represents an acid anion, such as those mentioned gzg f 'gf g above; R3 and R4 each represents a value given for R1 XXI ll-Diphenylamino-3,3'-diethyl-10,12-ethyleneoxatricarbocyanine perchlorate apd R2 above, Z2 and Z3 fireleach Selected from a villue XXII 1 1-Dimethylamino-3,3-diethyll0,12-ethylenethratncargiven for Z and Z above, Q represents a divalent linkbocyanine perchlorate age, such as ethylene, trimethylene, orthophenylene, XXIII 3,3'-Diethyl-l0,IZ trimethyIene-Il-thiomorpholinooxathiatricarboc anine perchlorate WhlCI'l linkage can be substituted, for example, with XXIV jjflmethyljoa12 ethy]ene ll (l decahydroquinolyn halogen, an alkyl or an alkoxy group of one to four car- 4,4'-tricarbocyanine perchlorate sents a member selected from the group consisting of 13525, ,f,; '?,th r;,;fine Salt alkyl and aryl, and, taken together R and R represent the non-metallic atoms required to complete a hetero- The enam'ne mcarbocyamne employed thls cyclic ring containing from five to six atoms, e.g., a l n can P P y reactmg one mol of an morpholino group, a thiomorpholino group, a piperi- Intermediate havmg formula m below:

dino group, a piperazinyl group, (preferably a 4-alkyl- 0 l-plperazinyl group such as methyl, ethyl, ethoxycarbo- 6 nyl, propyl or butyl groups, or a 4-aryl-l-piperazinyl III iI=(CH-CH);TC-CH=CH-N-C=-CH group such as a 4-phenyl-l-piperazinyl group) a pyr- 9 rolidinyl group, an indolinyl group, a tetrahydroquinoyl 1 3 6 group and a decahydroquinoyl group. Especially good results are obtained when Z2 and Z3 each represents a with one mol of an enamine salt of formula IV below:

benzoxazole, a naphthothiazole nucleus, or a benzothiazole nucleus; Q represents an ethylene linkage; and, 5 9 R R and R are taken together and represent a piperazi- II nyl group, 4-ethoxycarbonyl-l-piperazinyl being pre- 40 ferred. Z

Typical specific enamine tricarbocyanine dyes useful Q in the practice of this invention are set out in Table D Xe b to obtam a compound having formula V below:

Table D z Z 2 l l l-( 4-Ethoxycarb0nyl l -piperazinyl )-3,3 -diethyll O, l 2- N ethyleneoxatricarbocyanine perchlorate Q I II 3,3-Diethyl-l0,l2-ethylenel l-(4-methyll-piperazinyl- )oxatricarbocyanine perchlorate f (CH CH a- 1 c CH CH C C CH2 III 3,3'-Diethyl-lO,l2-ethyIene-l l-( 4-methyl-lpiperazinyl)- e thiatricarbocyanine perchlorate X R Q IV I l-( 4-Ethoxycarbonyll-piperazinyl )-3 ,3 '-diethyll 0, l 2- ethylene-5 ,5 '-diphenyloxatricarbocyanine perchlorate V Anh dro-I l-(4-eth0xycarbonyl-l-piperazinyl)-l0,l2-ethy- One mol of the compound of formula V above can then 1en@-3,3'-di(3-Sulf0Pr0Pyl)thialricarbocyanine hydroxide be reacted with one mol of a com ound havin formula VI AnhydroJOJZ-ethylene-ll-(4-methyl-l-piperazinyl)-3,3- VI b l p g di(3-sulfopropyl)oxatricarbocyanine hydroxide e VII Anhydro- I 0, l Z-ethylene-l l-(4-methyll -piperazinyl )-3,3 5 5 0 di( 3-sulf0propyl)thiatricarbocyanine hydroxide VIII l l(4-Ethoxycarbonyl-l-piperazinyl)-3,3'-diethyl-l0,l2- I 3 ethylenethiatricarbocyanine perchlorate VI CH -C 9 IX 1 l-(4-phenyl-lpiperazinyl)-3,3-diethyl10,12-ortho- \q C: CH CH :N phenylenethiatricarhocyanine p-toluene sulfonate C H b-l g X Anhydro-l l-dibutylaminol O, l 2-ethylene-3,3 -di( 3-sulfo- 6 5 propyl)thiatricarbocyanine hydroxide, sodium salt M X e XI 3 ,3 -Diethyll 0, l Z-ethylene-l l-( l-pyrrolidinyl )-thiatricarl bocyanine iodide X IO'ILEthYleng 1 1 3 3 3 3fl h p1 to obtain a compound having formula II above. In the rolidinyl)indotricarbocyanine iodide above formulas, X, a, b, Z Z Q R R R and R XIII 3,3'-Diethyl-l0,l2ethylene-l l-piperidinothiatricarbocyahave the meanings given above The reactions are ad nine iodide XIV 3,3 Diethyl-lO,lZ-ethylene-llmorpholinothiatricarvanta eousl conducted in a suitable solvent such as b d'd y ocyamne I0 I e XV 3.3'-Diethyl-l l-piperidino-l0,l2 trimethylenethiatricarg b ai iz izgggggggs sn z z gfi g l l t g Flu-es bocyanine iodide g U S [18 y am- XVI y lfii y H l-indolinyhoxutricarinc, and at elevated temperatures, such as the refluxing ocyamne perc ora e XV" 33, Diethyl lol2 ethylene 1HLUZJAdetrahy, temperature of the reaction mixtures. Further details droquinolyl]oxatricurbocyanine perchlorate on the preparation of dyes employed in this invention 9 appear in Jeffreys U.S. Pat. application Ser. No. 314,864 filed Oct. 10, 1963, now U.S. Pat. No. 3,483,195 and corresponding French Pat. No. 1,410,864; Jeffreys U.S. Pat. application Ser. No. 518,010 filed Jan. 3, 1966 now U.S. Pat. No. 3,506,655, and corresponding Belgian Pat. No. 674,800; Fumia et al U.S. Pat. application Ser. No. 574,947 filed Aug. 25, 1966 now U.S. Pat. No. 3,482,978 and corresponding Belgian Pat. No.

702,840; and, Fumia et al Ser. No. 22,708 filed Mar. 25, 1970 now U.S. Pat. No. 3,623,881. Supersensitization of these dyes with a sulfonated polynuclear aromatic organic supersensitizer, an azaindene or a silver halide reducing agent is described by Hiller et al in U.S. Pat. application Ser. No. 860,394 filed Sept. 23, 1969 now abandoned.

Merocyanine dyes are effectively employed in the practice of this invention. Typical useful merocyanine dyes have the following formula:

wherein R L and Z represents a value selected from those given above for R,, L and Z, respectively; c represents an integer of from 1 to 2; p represents an integer of from 1 to 3; and, Q represents the non-metallic atoms necessary to complete a fiveor six-membered 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., B-methyl-1-phenyl-2-pyrazolin-5-one, lphenyl-2-pyrazolin-5-one, l-(2-benzothiazolyl)-3- methyl-2-pyrazolin-5-one, etc.; an isoxazolone nucleus, e.g., 3-pheny1-5(4H)-isoxazolone, 3-methyl-5(4H)- isoxazolone, etc.; an oxindole nucleus, e.g., l-alkyl-Z- oxindoles, etc.; a 2,4,6-triketohexahydropyrimidine nucleus, e.g., barbituric acid or 2-thiobarbituric acid as well as their l-alkyl (e.g., l-methyl, l-ethyl, l-propyl, l-heptyl, etc.) or l,3-dialkyl(e.g., l,3-dimethyl, 1,3- diethyl, 1,3-dipropyl, 1,3-diisopropyl, 1,3-dicyclohexyl, l,3-di(B-methoxyethyl), etc.; or 1,3-diaryl (e.g., 1,3 diphenyl, 1,3-di-(p-chlorphenyl), 1,3-di(p-ethoxycarbonylphenyl), etc.); or l-aryl (e.g., l-phenyl, l-pchlorophenyl, l-p-ethoxycarbonylphenyl), etc.) or lalkyl-3-aryl (e.g., l-ethyl-3-phenyl, l-n-heptyl-3-phenyl, etc.) derivatives; at 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., etc.; a 2(3H)-imidazo[l,2-a]pyridone nucleus; a 5,7-dioxo-6,7-dihydro-5-thiazolo[3,2- a]pyrimidine nucleus, e.g., 5 ,7-dioxo-3-phenyl-6,7-dihydro-5thiazolo[3 ,2--

-a]-pyrimidine, etc.; a 2-thio-2,4-oxazolidinedione nucleus (i.e., those of the 2-thio-2,4(3H,5H)-oxazoled ione series) e.g., 3-ethy1-2 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-oxazolidinedione, etc.; a thianaphthenone nucleus, e.g., 3-(2ll)-thianaphthenone, etc.; a 2-thio-2,5-thiazolidinedione nucleus (i.e., the Z-thio- 2,5-(3H,4H)-thiazoledione series), e.g., 3-ethyl-2-thio- 2,5-thiazolidinedione, etc; a 2,4-thiazolidinedi0ne nucleus, e.g., 2,4-thiazolidinedione, 3-ethy1-2,4-thiazolidinedione, 3-phenyl- 2,4-thiazolidinedione, 3-a-naphthyl-2,4-thiazolidinedione, etc.; athiazolidinone nucleus, e.g., 4-thiazolidinone, 3-ethyl-4-thiazolidinone, 3-phenyl-4-thiazolidinone, 3-oz-naphthyl-4-thiazolidinone, etc.; a 2-thiaZo1in-4-one nucleus e.g., 2-ethylmercapto- 2-thiazolin-4-one, 2-alkylphenylamino-2*thiazolin- 4one, Z-diphenylamino-2-thiazolin-4-one, etc; a 2- imino-4-oxazolidinone (i.e., pseudohydantoin) nucleus; a 2,4imidazolidinedione (hydantoin) nucleus, e.g., 2,4-imidazolidinedione, 3-ethyl-2,4-imida2olidinedione, 3-phenyl-2,4-imidazolidinedione, 3-anaphthyl-Z,4-imidazolidinedione, l,3-diethyl-2,4- imidazolidinedione, 1-ethyl-3-phenyl-2,4-imidazolidinedione, 1-ethyl-3-a-naphthyl-2,4imidazolidinedione, 1,3-diphenyl-2,4-imidazolidinedione, etc; a 2- thi0-2,4-imidazolidinedione (i.e., 2-thiohydantoin) nucleus, e.g., 2-thio2,4-imidazolidinedione, 3-ethyl-2- thio-2,4-imidazolidinedione, 3-(4-sulf0butyl)-2-thio- 2,4-imidazolidinedione, 3-(2-carboxyethyl)-2-thio-2,4- imidazolidinedione, 3-phenyl-2-thio-2,4-imidazolidinedione, 3-anaphthyl-2-thio-2,4-imidazolidinedione, 1,3-diethyl-2-thio-2,4-imidazolidinedione, lethyl-3-phenyl-2-thio-2,4-imidazolidinedione, l-ethyl- 3-a-naphthyl-2-thio-2,4-imidazolidinedione, 1,3-dipheny1-2-thio-2,4-imidazolidinedione, etc.; a Z-imidazolin- 5-one nucleus, e.g., 2-propylmercapto-2-imidazolin- 5one, etc.; etc. (Especially useful are nuclei wherein Q represents the non-metallic atoms required to complete a heterocyclic nucleus containing five to six atoms in the heterocyclic ring, three to four of said atoms being carbon, And two of said atoms being selected from the group consisting of nitrogen, oxygen, and sulfur, and at least one of said two atoms being a nitrogen atom. Typical useful merocyanine dyes are described in Brooker et a1 U.S. Pat Nos. 2,493,747 and 2,493,748, both isued Jan. 10, 1950, and Knott U.S. Pat. No. 2,839,403 issuedJune17,1958.

Another preferred class of methine dyes include those comprising first and second nuclei joined by a double bond or methine linkage (including one or more methine groups); the first of said nuclei being selected from the group consisting of (1) a nitrogen-containing heterocyclic nucleus of the type used in cyanine dyes having from five to six non-metallic atoms in the heterocyclic ring, and (2) a nitrogen-containing heterocyclic ketomethylene nucleus of the type used in merocyanine dyes having from five to six non-metallic atoms in the heterocyclic ring, joined in each instance by a carbon atom of l) or (2) to said linkage; and said second nucleus being an enamine group selected from the group consisting of a 1-(3,4,4a,5,6,7-hexahydro-2- naphthyl)pyrro1idine group, a l-(3,3a,4,5-tetrahydro- 2H-inden-6-yl)pyrrolidine group, a 1-(2-norbornylidene)pyrroline group and a 1-(1-indanylidene)pyrrolidine group, joined at a carbon atom thereof to said linkage, to complete said dye. Preferred dyes of this type include those represented by the following formulas:

wherein e and g each represents a positive integer of from 1 to 2; f represents a positive inteer of from 1 to 3; L represents a methine linkage, e.g., =CI'I, =C(CH =C(C H etc.; D represents an enamine group selected from a 2,3,4,4a,5,6-hexahydro-7- (1-pyrrolidinyl)-l-naphthyl group, a 2,6,7,7a-tetrahydro-5-(1-pyrrolidinyl)-3-indenyl group, a 3-(l-pyrrolidinyl)-2-norbornen-2-yl group or a 3-(1-pyrrolidinyl)-2-indenyl group, represented by the following basic structures:

and

which groups can be further substituted on appropriate nuclear carbon atoms thereof by alkyl, e.g., methyl, butyl, etc., or alkoxy, e.g., methoxy, butoxy, etc., and the like; R X and Q represents a value given above for R X and Q, respectively. Methine dyes of this type can be conveniently prepared in a number of ways. For example, a number of the dyes defined by formua VIII above are advantageously prepared by heating a mixture of (1) a heterocyclic salt of the formula:

wherein f is 2 or 3; e, L, R X and Z are as previously defined, and R represents a hydrogen atom or an acyl group, e.g., acetoxy, phenoxy, etc., with (2) an enamine intermediate selected from the group consisting of a l-(3,4,4a,5,6,7-hexahydro-2-naphthyl)pyrrolidine, or a l-(3,3a,4,5-tetrahydro-2H-inden-6-yl)pyrrolidone, or a l-(2-norbornylidene)pyrrolidinium salt, e.g., the chloride, bromide, iodide, perchlorate, p-toluenesulfonate, etc. salt, or a l-(l-indanylidene)pyrrolidinium salt, e.g., the chloride, bromide, iodide, perchlorate, p-toluenesulfonate, etc. salt, in approximately equimolar proportions, in a solvent medium such as ethanol, pyridine, N,N-dimethylacetamide, acetic anhydride, etc. Advantageously, a basic condensing agent such as triethylamine is used with the acetic anhydride reaction medium. The dyes are then separated from the reaction mixtures and purified by one or more recrystallizations from appropriate solvents such as methanol, mixtures of pyridine and methanol, and the like. The dyes wherein the value of f is l in formula VIII above are advantageously prepard with l) a heterocyclic salt of the formula:

wherein g, R X and Z are as previously defined and R represents an alkyl or aryl group, e.g., methyl, butyl, phenyl, etc., and (2) an enamine intermediate above defined, under generally similar reaction conditions and purification of the dyes as described in the preceding procedure. The dyes defined by formula IV above are also prepared by the above procedure described for the dyes of formula VIII using the same enamine intermediates except that the heterocyclic salt of formula X is replaced by a ketomethylene heterocyclic compound of the formula:

wherein g, L, R and Q are as previously defined. Dyes of this type are described in Fumia et al US. Pat. No. application Ser. No. 830,483 filed June 4, 1969, now US. Pat. No. 3,655,392, and include such dyes as 3-ethyl-2-{2-[2 ,3 ,4 ,4a ,5 ,6-hexahydro-7-(l -pyrrolidinyl)-1-naphthyl]vinyl}benzoxazolium iodide; 3- ethyl-2-{2-[2 ,3 ,4 ,4a ,-5 ,6-hexahydro-7-(1 -pyrrolidinyl)-l-naphthyl] vinyl}benzothiazolium iodide; 3- ethyl-5 [2 ,3 ,4 ,4a,5 ,6-hexahydro7-( 1 -pyrr0lidinyl)- 1-naphthyl]methylene}rhodanine; 3-ethy1-2-[2,6,7,7atetrahydro-S-(l-pyrrolidinyl)-3-indenyl]benzothiazolium perchlorate; 3-ethyl-2-{2-[2,6,7,7a-tetrahydro-5 1 -pyrrolidinyl)-3 -indenyl] -vinyl}benzoxazolium iodide; 3-ethyl-2-{2-[2,6,7,7a-tetrahydro-5- (1pyrrolidinyl)-3-indenyl]vinyl}benzothiazolium iodide; 3-phenyl-4-{ [2 ,6 ,7 ,7a-tetrahydr0-5-(1-pyrrolidinyl)-3-indenyl]methylene}-2-isoxazolin-5-0ne; 3-methyl- 1 -phenyl-4-{ [2 ,6 ,7 ,7a-tetrahydro-5 (l -pyrrolidinyl)-3-indenyl-]methylene} -2pyrazolin-5-one; 3-ethyl-5-{ [2 ,6 ,7 ,7a-tetrahydro-5-( 1 -pyrrolidinyl)- 3- indenyl]methylene}rhodanine; 3-ethyl-2-{2-[3-(1-pyrrolidinyl)- Z-norbornen-Z-yl]vinyl}benzoxazolium perchlorate; 3-ethyl-2-{2-[3-(l-pyrrolidinyl)-2-norbornen-2-yl]vinyl}benzothiazolium perchlorate; l-ethyl-Z- {2-[3-(l-pyrrolidinyl)-2-norbornen-2-yl]vinyl}naphtho[1 ,2-d]thiazolium perchlorate; 1,3 ,3-trimethyl-2- {2-[3-(1-pyrrolidinyl)-2-indenyl]vinyl}-3H-indolium perchlorate; 3-ethyl-2-{2-[3-(l-pyrrolidinyl)-2- indenyl]vinyl}-benzoxazolium perchlorate; 3-ethyl-2- {2-(3-(1-pyrrolidinyl)-2-indenyl]vinyl}benz0- thiazolium perchlorate and 1-ethyl-2-{2-[3-(1-pyrrolidinyl)-2-indenyl]vinyl}naphtho[1 ,2 ,-d]thiazolium perchlorate.

Another highly useful class of dyes are enamine methine dyes which contain a double bond remote from the chromophoric chain. Such useful enamine dyes include cyanine, hemicyanine and hemioxonol dyes. Such dyes can have formula II above wherein R and R taken separately, each represents an allyl group, or R and R taken together, represent the atoms required to complete a l,2,5,6-tetrahydro-l- Still other useful dyes of this class have the following formula:

CH3 CH Enamine dyes containing a double bond remote from similar to the preparation of the enamine dyes of formulas 11, VIII and IX above, but using one of the following starting materials;

. the chromophoric chain can be prepared in a manner Intermediate A l-Cyclopentylidene-3-pyrrolinium 3-Pyrrolinium perchlorate (17.0 g) and 3-pyrro1ine (4 drops) are suspended in ethanol ml) and the suspension heated on a steam bath to obtain a solution.

Cyclopentanone (10.1 g) is then added to the hot solution and solid precipitated. The mixture is heated to reflux and then chilled. The solid is collected on a filter and the yield is 22.5 g mp. 202203 C.dec.

CH3 CH3 (mar en -CH Intermediate B 1-Isopropylidene-3-pyrrolinium perchlorate 1| C 1 ne CH C-CH3 A solution of 3-pyrroline (14.5 g) in ether (1.1) is treated with 72% perchloric acid (28.0 g) with stirring and cooling. Decanted, stirred residue with a fresh portion of ether (1 1.), decanted and then suspended the residue in ethanol ml). Acetone l I .6 g) is added, the mixture is heated to reflux and then chilled. The solid is collected on a filter and then recrystallized from ethanol. The yield is 28 g (67%), mp. l68l69 C. dec. In preparing dyes from this compound, it is necessary to have acetic anhydride present which indicates that the compound may be a hydrate.

Intermediate C Cyclopentenylidenediallylammonium perchlorate Cyclopentanone (25.2 g), diallylamine (49.0 g), ptoluene sulfonic acid (0.5 g) and benzene (90 ml) are placed in an apparatus designed for the continuous removal of water and heated at reflux for 16 hours. After evaporation under reduced pressure, the residue is distilled in vacuum to yield the enamine (b.p. -93 C/l5 mm Hg). The enamine so obtained is dissolved in ether (1 1.), and the cooled solution treated with 72% perchloric acid until the mixture is just acid. Decanted, stirred residue with a fresh portion of ether (1 1.), decanted and then recrystallized the solid from ethanol. The yield is 42.8 g (54%), m.p. 122-123 C dec.

Intermediate D l-(5,5-'Dimethyl-3-methylene-lcyclohexenl -yl )-3-pyrroline H30 CH3 lsophorone (41.4 g), 3-pyrroline (31.0 g), p-toluene sulfonic acid (0.5 g) and benzene (90 ml) are placed in an apparatus designed for the continuous removal of water and heated at reflux for 1 hour. After evaporating under reduced pressure, the residue is distilled in vacuum. Decomposition takes place during the distillation with 12.1 g (21%) of the desired material being obtained. (b.p. 8995 C/0.4-l.lmm Hg) Intermediate E 5,5-Dimethyl-3-(3-pyrrolin-l-yl)-2- cyclohexen- 1 -one To a solution of 5,5-dimethyl-3-( 3-pyr rolin-l-yl)-2- cyclohexen-l-one (37.5 g) in benzene (300 ml) is added phosphorous pentachloride (40.8 g). The mixture is heated to reflux and then removed from heat until the initial reaction has subsided. The reaction is then heated at reflux for 2 %hours. After cooling, the mixture is stirred with ice water (-300 ml). The water layer is removed and an aqueous solution of sodium perchlorate (36 g/-l00 ml) is added to it. After chilling, the solid is collected on a filter and dried. The crude yield is 40.5 g (67%). After one recrystallization from ethanol, the yield is 29.5 g (49%), mp. 140l4l C dec. 1 Intermediate G l-Cyclopentylidene-l,2,5,.6-tetrahydropyridinium perchlorate 1 l,2,5,-Tetrahydropyridine (8.7 g) and cyclopentanone (10.7 g) are dissolved in ethanol (25 ml) and the solution treated with 72% perchloric acid (14.0 g) with cooling. The mixture is then heated at reflux for 15 minutes and, after chilling, the solid is collected ona filter. The yield is 16.6 g (66%), mp. 230 23l C dec.

Representative useful enamine dyes having a double bond remote from the chromophoric chain, and the preparation thereof, are given below: 3-Ethyl-2-[4-( 3-pyrrolinl -yl )-3 ,4-trimethylenel ,3-

'butadienyl]-benzoxazolium perchlorate N o I clo l-Cyclopentylidene-3-pyrrolinium perchlorate 1,3 g), 2-( 2-acetanilidovinyl)-3-ethylbenzoxazolium iodide (2.2 g), and triethylamine (1.5 m1) are dissolved in acetic anhydride (15 ml) and stirred at room temperature for 15 minutes. The solid is collected on a filter and, after two recrystallizations from methanol, the yield of purified dye is 0.5 g (25%), mp. 262263 C dec. 3,3 -Diethyl-10,12-ethylene-l l-( 3-pyrrolinl -yl)oxatricarbocyanine perchlorate v 0 H ClOf l-Cyclopentylidene-3-pyrrolinium perchlorate 1.2 g), 2-(2-acetanilidovinyl)-3-ethylbenzoxazolium iodide (4.8 g), and triethylamine (1.5 ml) are dissolved in acetic anhydride (15 ml) and heated at reflux for 10 minutes. After cooling to room temperature, the solid is collected on a filter, washed with methanol and then recrystallized from cresol/methanol. The yield of puri- 3-Ethyl-2-[4-( 3-pyrrolin- 1 -yl) 1 ,3-pentadienyl1benzoxv 010 e 0 H; Ll

l-lsopropylidene-3-pyrrolinium perchlorate (2.3 g), 2-( 2-acetanilidovinyl)-3-ethylbenzoxazolium iodide (4.3 g), acetic anhydride (1.0 ml) and triethylamine 1.7 ml) are dissolved in ethanol (20 ml) and heated at reflux for 10 minutes. After chilling, the solid is col lected on a filter and then recrystallized from methanol. the yield of purified dye is 1.1 g (29%), mp. 223-224 C dec.

3-Methyl-2-[4-( 3-pyrrolin- 1 -yl) l ,3-pentadienyl]- thiazolium perchlorate 1-lsopropylidene-3-pyrrolinium perchlorate (2.3 g), 2-(2-anilinovinyl)-3-methyl-2-thiazolium iodide (3.5 g), acetic anhydride (2.0 ml), and triethylamine (3.4 ml) are dissolved in acetonitrile (20 ml) and heated at reflux for 10 minutes. After chilling, the solid is collected on a filter and then recrystallized from methanol. The yield of purified dye is 1.2 g (36%), m.p. 223-224 C dec. 2[2-(2-Diallylamino-1-cyclopentenyl)viny1l-3-ethylbenzothiazolium perchlorate H26 CH2 2 c Cyclopentenylidenediallylammonium perchlorate (2.9 g), 2-(2-acetanilidovinyl)-3-ethylbenzothiazolium iodide (4.5 g) and triethylamine (1.4 ml) are dissolved in acetonitrile ml) and heated at reflux for 5 minutes. After chilling, the crude dye is collected on a filter and recrystallized from methanol with the methanol solution being treated with norite. The yield of purified dye is 1.47 g (33%), m.p. 219-220 C dec. 1 l-Diallyamino-3 ,3 -diethyll O, l 2-ethyleneoxatricarbocyanine perchlorate Cyclopentenylidenediallylammonium perchlorate (1.32 g), 2-(2-acetanilidovinyl)-3-ethy1benzoxazolium iodide (4.56 g) and triethylamine (1.5 ml) are dissolved in N,N-dimethylacetamide (10 ml) and heated at a gentle reflux for 5 minutes. The reaction mixture is diluted to -300 ml with boiling methanol and, after chilling, the dye is collected on a filter (0.97 g, 32%). After one recrystallization from methanol, the yield of purified dye is 0.64 g (21%), m.p. 229230 C dec. 5 2-Diallylaminol -cyclopentenyl)methylene-3- ethylrhodanine C H5 n N O 6 s 5-Acetanilidomethylene-3-ethylrhodanine (3.06 g), cyclopentenylidenediallylammonium perchlorate (2.64 g) and triethylamine (1.5 ml) are dissolved in N,N- dimethylacetamide (15 ml) and heated at a gentle reflux for 5 minutes. The reaction mixture is diluted to 300 ml with boiling methanol and, after chilling, the dye is collected on a filter. The yield is 0.40 (12%), m.p. 127-l28 C dec. 3-Ethyl-2-[4,6-neopentylene-6-(3-pyrrolin-1-yl)-- -l ,3,S-hexatrienyl]benzothiazolium iodide clof aqueous solution of sodium perchlorate (1.0 g/-5 ml) is added and, after chilling, the crude dye is collected on a filter. After one recrystallization from methanol, the yield of purified dye is 0.5 g (21%), m.p. 23 l-232 C dec.

3-Ethyl-5- 3 ,5neopentylene-5-( 3-pyrrolinl -yl )-2,4- pentadienyliden]rhodanine 5-Acetanilidomethylene-3-ethylrhodanine (3.1 g) and l-(5,S-dimethyl-3-methylene-l-cyclohexen-l-yl)- 3-pyrroline (2.1 g) are dissolved in N,N-dimethylacetamide (15 ml) and heated at a gentle reflux for 5 minutes. After diluting with -30O ml of boiling methanol, the mixture is allowed to stand at room temperature for 3-Allylrhodanine (1.73 g), l-(3-chloro-5,5-dimethyl- 2-cyclohexen-1-ylidene)-3-pyrrolinium perchlorate (3.10 g) and triethylamine (3.1 ml) are dissolved in ethanol (20 ml) and heated at reflux for 1 minute. The mixture is allowed to stand at room temperature for 30 minutes and then the crude dye is collected on a filter. After one recrystallization from pyridine/methanol, the yield of purified dye is 2.36 g (68%), m.p. 202203 C dec. 5-[5 ,5-Dimetl1yl-3-( 3-pyrrolin- 1 -yl )-2-cyclohexenylidene -3-ethyl- 1-phenyl-2-thiohydantoin 1-( 3-Chloro-5 ,5 -dimethyl-2-cyclohexenl -ylidene 3-pyrrolinium perchlorate (3.10 g), 3-ethyl-l-phenyl- 2-thiohydantoin (2.2g) are triethylamine (3.1 ml) are dissolved in ethanol ml) and heated at reflux for 10 minutes. After chilling, the crude dye is collected on a filter and then recrystallized from methanol. The yield of purified dye is 1.50 g (38%), m.p. 219220 C dec. 3-Ethyl-2-[4-( l,2,5,6-tetrahydro-l-pyridyl)-3,4- trimethylenel ,3-butadienyl]benzoxazolium perchlorate o Q CH=CH l-Cyclopentylidene-l ,2,5 ,6-tetrahydropyridinium perchlorate (2.7 g), 2-( 2-acetanilidovinyl)-3-ethylbenzoxazolium iodide (4.3 g) and triethylamine (1.5 ml) are dissolved in acetic anhydride (20 ml) and stirred at room temperature for 2 hours. The crude dye is collected on a filter and then recrystallized from methanol. The yield of purified dye is 0.9 g (21%), m.p. 214215 C dec. 3-Ethyl-2-[ 4-( 1,2,5 ,6-tetrahydrol -pyridyl )-3 ,4- trimethylene- 1 ,3-butadienyl]benzothiazolium perchlorate l-Cyclopentylidene-l ,2,5 ,6-tetrahydropyridinium perchlorate (2.7 g), 2-(2-acetanilidovinyl)-3-ethylbenzothiazolium iodide (4.5 g) and triethylamine (1.5 ml) are dissolved in acetic anhydride (20 ml) and the mixture stirred at room temperature for 1 hours. The crude dye is collected on a filter, rinsed with ethanol and then recrystallized twice from methanol. The yield of purified dye is 1.0 g (23%), m.p. 227-228 C dec. 3,3 -Diethyl-10,12-ethylene-l l-( 1,2,5 ,6-tetrahydrolpyridyl)-oxatricarbocyanine perchlorate 1 -Cyclopentylidene- 1 ,2 5 ,6-tetrahydropyridinium perchlorate (1.2 g), 2-(2-acetanilidovinyl)-3-ethylben- Zoxazolium iodide (4.8 g) and triethylamine (1.5 ml) are dissolved in acetic anhydride (20 ml) and heated at reflux for 5 minutes. The hot mixture is turned into a beaker, stirred for 2 minutes and the solid then col lected on a filter. After one recrystallization from N,N- dimethylacetamide, the yield of purified dye is 1.1 g (37%), m.p. 25l-252 C dec. 3-Ethyl-5-[2-(3-pyrrolin-1yl)-l-cyclopentenylmethylene -rhodanine H CH: N025 21 Cyclopentylidene-3-pyrrolinium perchlorate (2.36 g), -acetanilidovinyl-3-ethylrhodanine (3.06 g), and triethylamine (1.5 ml) are dissolved in ethanol ml) and heated at reflux for 5 minutes. After chilling, the

wherein n, m, d and g each represent a positive integer of from 1 to 2; L represents a methine linkage; J and G each represent a member selected from the group consisting of oxygen, sulfur, selenium and the group =l l--R such that at least one of J and G represent said =N-R group; A represents a member selected from the group consisting of oxygen, sulfur, selenium and the group =NR R represents a member selected from the group consisting of an alkyl group, a cycloalkyl group and an aryl group; R and R each represents a member selected from the group consisting of an alkyl group, an alkenyl group and an aryl group; represents an acid anion; Z Z and Z each represent the non-metallic atoms necessary to complete a heterocyclic nucleus having five or six carbon atoms and preferably the heterocyclic nucleus is selected from the group consisting of a thiazole nucleus, an oxazole nucleus, a selenazole nucleus, a 3,3-dialkylindolenine nucleus and an imidazole nucleus; and Q1 represents the non-metallic atoms necessary to complete a heterocyclic nucleus of five or six carbon atoms with preferred nuclei a 2-thiazolin-4-one nucleus, a 2-thioxo-4-imidazolidone nucleus, a 2-pyrazolin-5-one nucleus, a 2-thioxo- 4,6-pyrimidinedione nucleus and a 2-thioxo-4- thiazolidinone nucleus.

Exemplary of the dyes of Formula XIV are the following typical dyes:

3-ethyl-5-[ 3-methyl-2-thiazolidinylidene )ethylidene -2-[ 3-methyl-2-thiazolidinylidene l propenyl]-4-oxol-phenyl-Z-imidazolinium iodide 22 2-[2-benzothiazolyletho-p-toluenesulfonate)methylene]-5-[( l,3-diethyl-2-(3H)benzimidazolylidene)ethylidene]-3-ethyl-4thiazolidone crude dye is collected on a filter and, after one recrys- 5 l-ethyl-4-[(3-ethyl-2( 3H)-benzoxazolylidene) tallization from benzene, the yield of purified dye is a h 1id 2 3- h 1 2( 3fl)b l id l g p- 1990-2000 C propenyl1-5-oxo-3-phenyl-2-imidazolinium iodide. y y 'l -Py 'y y p Exemplary of the dyes of Formula XV are the followtenylmethylene]rhodanine, sodium salt ing dyes;

y y p y -py 2-[(Z-diphenylamino-4-oxo-2-thiazolin-5-ylidene)erolinium perchlorate (3.39 g), 3-carboxymethylrhoda- 1 3 1 1 5 1 3 3 i 1 2 nin g) acetic anhydride and triethylindolinylidene)-ethylidene]-4-imidazolidinone amine (3.0 ml) are dissolved in 4-butyrolactone (15 2 1 l 4 -3 h l g i 5 ml) and heated at a gentle reflux for 5 minutes. A soluimidazolidenylidene 1 3 1-1 1 tion of sodium iodide (2.00 g) in acetonitrile (50 ml) is 15 5 1 3 3 1 g 14- added and, after cooling, the crude dye is collected on imidazolidinone a filter. After one recrystallization from N,N-dime- 2 1 i l 3 1-5 -g li thylacetamide/acetonitrile and another from water- 4 ylidene] ethylidene 3 1 5 3- 2 b /acetonitrile, the yield is 0.31 g (9%), mp. 25725 8 zoxazolinylidene) ethy1idene] 1 pheny1 4 C 20 imidazolidinone Yet still another class of useful dyes are the trinuclear 1,3 diethyl-5-[(3-ethyl-2-benzoxazolinylidene complex cyanine and merocyanine dyes described in h 1id ]-2 [(1- h lh h d 4 6 di g hi et a1. Pat. NO. having the Stl'llC- xo s-pyrimidinylidene)ethylidene1-4-imidazoliditures: none l,3-diethyl-5-[ 3-ethyl-2-benzoxazolinylidene )ethylidene -2-[ 3-m ethyl-5 -oxol -phenyl-2-pyrazolin-4-ylidene)ethylidene]-4-imidazolidinone 3-ethyl-5- 3-ethyl-2- benzothiazolinylidene )ethylidene -2 3-methyl-5 -oxol -phenyl2-pyrazolin-4-ylidene)ethlidene1-1-phenyl-4-imidazolidinone 3-ethyl-5-[(3-ethyl-2-benzothiazolinylidene )isopropylidene -2- 3 -ethyl-4-oxo-2-thioxo-5- thiazolidinylidene)ethylidene1- l-phenyl-4- imidazolidinone 2-[ 3-methyl-5-oxo-l -phenyl-2-pyrazolin-4- ylidene)ethylidene]- 1 -phenyl-5-[( 1,3 ,3-trimethyl- 2-indolinylidene)ethylidene]-4-imidazolidinone 3-( 3-diethylaminopro pyl )-2-[ 3-dimethylaminopropyl)-4-oxo-2-thioxo-5-thiazolidinylidene]-5- l-ethylnaphtho[ l ,2-d]-thiazolin-2-ylidene l phenylethylidene]-4-thiazolidinone 2-( l,3-diethylhexahydro-4,6-dioxo-2-thioxo-5- pyrimidinylidene)-3-ethyl-5-[ 3-ethyl-2-benzothiazolinylidene)-1-phenylethylidene]-4-thiazolidinone 3-ethyl-5-[ 3-methyl-2-thiazolidinylidene )e thylidene]-2-[ 3-ethyl-4-oxo-2-thioxo-5- thiazolidinylidene )ethylidene l -phenyl-4- imidazolidinone. 1

Still yet another class of dyes useful according to the present invention are the tetranuclear dyes of Jenkins U.S. Pat. No. 3,558,614 having the structure:

wherein R R R R R and R each represents a group selected from the class consisting 'of an alkyl group and an aryl group; B and B each represents an atom selected from the class consisting of oxygen, sulfur and selenium; X represents an anion; d and q each represents an integer of from I to 2; n, m and p each represents an integer of from 1 to 3; L represents a methine group; Z and Z each represents the nonmetallic atoms required to complete a heterocyclic nucleus having from five to six atoms in the heterocyclic ring and preferably the heterocyclic ring is selected from the class consisting of a thiazole nucleus, a benzo- I thiazole nucleus, at naphthothiazole nucleus, a thianaphtheno-7',6,4,5-thia2ole nucleus, an oxazole nucleus, a benzoxazole nucleus, a naphthoxazole nucleus, a selenazole nucleus, a benzoselenazole nucleus, a naphthoselenazole nucleus, a thiazoline nucleus, a pyridine nucleus, a quinoline nucleus, an isoquinoline nucleus, a 3,3-dialkylindolenine nucleus, an imidazole nucleus, a benzimidazole nucleus and a naphthimidazole nucleus.

Exemplary of the dyes of Formula XVI are the following:

3 ,3 -diethyl- ,5 -di( 3-ethyl-2-benzothiazolinylidene)-4,4-dioxol ,1 diphenylimidazolinocarbocyanine perchlorate 3,3'-diethyl-5,5'-di[(3-ethyl-2-benzoxazolinylidene)ethylidene]-4,4'-dioxo-1,1 diphenylimidazolinocarbocyanine iodide 1,1 '3 ,3 -tetraethyl-4,4 '-dioxo-5 ,5-di[( 13 ,3-trimethyl-Z-indolinylidene)ethylidene]imidazo- XIX.

linocarbocyanine iodide I 3 ,3 '-diethy1-5,5 '-di( l-ethylnaphtho[ l,2-d]thiazolin- 2-ylidene-4,4 -dioxo-l ,1 '-diphenylimidazolinocarbocyanine perchlorate trimethyl-2-indolinylidene)ethylidene]imidazolinocarbocyanine iodide 3,3 '-diethyl-5 ,5 '-di[ 3-ethyl-2-benzothiazolinylidene )ethylidene ]-4,4 -dioxo-l ,l diphenylimidazolinocarbocyanine iodide 5 ,5 -di[ 3 ,3-dimethyl-l-S-sulfobutyl-1I-I-benz(e)indolin-2-ylidene )-ethylidene]-3 ,3 -diethyl-4,4 dioxol 1 '-diphenylimidazolinocarbocyanine dide disodium salt.

It is sometimes desirable to supersensitize the dyes employed in this invention. Preferred supersensitizers are the polynuclear aromatic compounds containing at least one sulfo group. The term polynuclear aromatic as used herein is intended to mean two or more benzene rings fused together (for example, as in naphthalene, pyrene, etc) or at least two benzene rings or aromatic rings directly joined together (for example, as in diphenyl, terphenyl, quaterphenyl, etc) or through an aliphatic linkage. Such sulfonated derivatives can conveniently be presented by the following general formula:

TSO M wherein T represents a polynuclear aromatic group as defined above and M represents a hydrogen atom or a water-soluble cation salt group (e.g., sodium, potassium, ammonium, triethylammonium, triethanolammonium, pyridinium, etc). Among the most useful of the sulfonated derivatives embraced by Formula XVII above are the compounds represented by the following general formula:

XVIII 2 wherein T represents, a l,3,5-triazin-6-ylamino group, T represents an aromatic group (i.e., benzene or substituted benzene) and M has the values given above.

Typical of the sulfonated derivatives of Formula XVIII above, wherein T represents, a 1,3,5-triazin-2- ylamino group (i.e., a 1,3,5-triazin-2-ylamino group) are the compounds selected from those represented by the following general formula:

T W Y CH=CH f 21 22 wherein M has the values given above and R R R R each represents a hydrogen atom or a substituent group, such as hydroxyl, aryloxyl (e.g., phenoxyl, otoloxyl, p-sulfophenoxyl, etc.), alkoxyl(e.g., methoxyl, ethoxyl, etc.), a halogen atom (e.g., chlorine, bromine, etc.), a heterocyclic radical (e.g., morpholi'nyl, piperidyl, etc.), an alkylthio group (e.g., methylthio, ethylthio, etc.), an arylthio group (e.g., phenylthio, t0- lylthio, etc.), a heterocyclylthio group (e.g., benzothiazylthio, etc.) an amino group, an alkylamino group (e.g., methylamino, ethylamino, propylamino, dimethylamino, diethylamino, dodecylamino, cyclohexylamino, ,B-hydroxyethylamino, di-B-hydroxyethylamino, B-sulfoethylamino, etc.), an arylamino group (e.g., anilino, 0-, mand p-anisylamino, 0-, mand pchloroanilino, o-, mand p-toludino, o-, m-, and pearboxyanilino, hydroxyanilino, sulfonaphthylamino, o-, mand p-aminoanilino, p-acetamidanilino, etc.), etc.

Compounds of Formula XIX wherein R R R and/or, R each represents a heterocyclylamino group (e.g., Z-benzothiazoleamino, 2-pyridylamino, etc.) can also be used in practicing my invention.

Another group of sulfonated derivatives which are useful in practicing the invention are those represented by the following general formula:

o \\s//o a1, U.S. Pat. No. 2,684,966, datedJuly27,1954;Zweidler et al, U.S. Pat. No. 2,784,197, dated Mar. 5, 1957; and Keller et a1, U.S. Pat. No. 2,784,183, dated Mar. 5, 1957. A somewhat related group of compounds containing a 2-benzotriazolyl group which can be used in this invention have been previously described in U.S. Pat. No. 2,733,165. Such compounds are embraced by Formula IVa above.

Typical sulfonated derivatives embraced by Formulas XVII, XVIII, XX and Vla above are (chemical formulas are given for various types to aid in identification):

1. a sulfonated triazolostilbene, e.g., of the type shown in U.S. Pat. No. 2,713,057.

4-methyl-2-methoxybenzamido, l-naphthoylamino, 2- naphthoylamino, 2,4-dimethoxybenzamido, Z-phenylbenzamido, 2-thienylbenzamido) or a sulfo group, R represents an acylamido group (e.g., as defined by R above), or a sulfoaryl group (e.g., sulfophenyl, p'-sulfodiphenyl, etc.) and R represents a hydrogen atom or a sulfo group, said compound containing at least one sulfo group.

Compounds of Formula XIX which can advantageously be employed in practicing my invention have been described in one or more of the following representative patents:

2,171,427 August 29, 1939 2,472,475 June 14, 1949 2,595,030 April 29, 1952 2,660,578 November 24, 1953 2,945,762 July 19, 1960 British:

595,065 November 26, 1947 623,849 May 24, 1949 624,051 May 26, 1949 624,052 May 26, 1949 678,291 September 3, 1952 681,642 October 29, 1952 705,406 March 10, 1954 The products of Formula XIX have been previously employed in the textile field, and are sold under such tradenames as Leucophor B, Calcofluor White MR, Tinopal (SP, WR, BV277, 2B, GS, NG), Blancofor SC, Hiltamine (BSP, N, 801., 6T6), and the like.

The dibenzothiophenedioxide compounds of Formula XX have, in general, been previously described in the prior art. See, for example, U.S. Pat. Nos. 2,573,652; 2,580,234; and 2,563,493. Further examples of the preparation of such compounds are given in J. E. Jones, J. Spence, and J. A. VanAllan, U.S. Pat. No. 2,937,089, issued May 17, 1960. Still other examples of compounds represented by Formula XVII above which can be used in my invention have been previously described in B. H. Carroll, J. E. Jones, and J. Spence, U.S. Pat. No. 2,950,196, issued Aug. 23, 1960. (See, in particular, the compounds of Formulas II, III and IV of that patent).

Compounds selected from those of Formula XVIII above wherein T represents a Z-benzotriazolyl group can be prepared according to methods previously described in the prior art. See, for example, Zweidler et al U.S. Pat No. 2,713,057, dated July 12, 1955; Keller et 4,4'-di(4,6"-dihydroxy-2"-s-triazinylamino)stilbene-2,2-disulfonic acid 3. 4,4-bis[4-(3-sulfoani1ino)-6-amino-s-triazine-2- ylamino]-stilbene 4. Tinopal-WR, a sulfonated triazinyl stilbene 5. Tinopal-2B, a sulfonated triazinyl stilbene 6. A sulfonated traizinyl stilbene, e.g., of the type shown in U.S. Pat. No. 2,595,030 or British Pat. No. 595,065

4,4-bis[ 2-( 4-sulfoanilino-ZB-hydroxyethylamino)-1,3,5-triazin-6-ylamino]stilbene-2,2 disulfonic acid 8. 4,4-bis(2,4-dihydroxy-1,3,5-triazin-6-ylamino)dibenzyl-2,2-disulfonic acid 4,4 -bis( 2-B-hydroxyethylamino-4-anilino-1 ,3 ,5- triazin-6-ylamino)-1 ,4-distyrylbenzene-2,2'-disulfonic acid 10. 5-methoxy-2-(4-styryl-3-sulfo)phenyl-1,2,3,-benzotriazole sodium salt 11. Calcofluor White-MR, a sulfonated triazinyl stilbene 27 4-[4-chloro-6-di( B-hydroxyethyl )aino-s-traizin-2- ylamino]-stilbene-2,2'-disulfonic acid 20. 2,8-bis[4-(4-sulfoanilino)-6-hydroxy-s-triazin-2- ylamino]-carbazole 21 4,4-bis(4,6-di( B-hydroxyethylamino)-s-triazin- 2-yl) benzidine-2,2'-disulfonic acid 22. 2-laurylamino-4,6-di( 4 sulfoanilino)-s-triazine )aminoanilino]-6-hydroxy-s-triazin-2-ylamino stilbene-2,2-disulfonic acid 24. -acetamido-2-( 4-styryl-3-sulfo )phenyl-I ,2,3-

benzotriazole sodium salt 25. 2,7-diacetamido-3,6-disulfodibenzothiophene- 5,5-dioxide sodium salt 26. 4-sulfo-o-terphenyl sodium salt [Lour. Organ.

Chem., Vol. 14 (1949), pg. 163] 27. pyrene-3-(4-methoxy-3-sulfostyryl)ketone sodium salt 28. 3,7-bis(4-methyl-2-methoxybenzamido)-2,8-

disulfodibenzo-thiophene-S,5-dioxide sodium salt As can be seen above, many of the sulfonated derivatives are employed in the form of their water-soluble salts, such as alkali metal (e.g., sodium, potassium, etc.) salts, or ammonium or amine (e.g., triethylamine, triethanolamine, pyiridine, aniline, etc.) salts. By thus using these derivatives, they can be added to the emulsions in substantially neutral aqueous solutions without disturbing the pH of the emulsions.

In accordance with the practice of this invention, any reducing agent (i.e., a material capable of reducing silver halide) can be employed which supersensitizes photographic silver halide emulsions containing methine dyes of the type employed herein. Particularly good results are obtained with dihydroxy substituted reducing agents. Typical dihydroxy compounds which can be employed in the practice of this invention are selected from the group consisting of the benzenes, gamma-lactones, pyronimides, tetronimides, furans and pyrroles, which contain at least two hydroxyl groups.

Typical useful dihydroxy substituted compounds which can be utilized include hydroquinone, resorcinol, pyrocatechol, 3-methylpyrocatechol, toluhydroquinone, naphthalenediols, etc.; 'y-lactones such as ascorbic acid, isoascorbic acid, etc.; 3-hydroxy tetronimides; 3,4,5-trihydroxy-5,6-dihydro-pyronimides; and amino hexose reductones wherein the moiety comprising the subject reductones can be represented by the following formula Y R -N- wherein R and R can be an alkyl radical, preferably having one to eight carbon atoms or together the necessary atoms to make a heterocyclic radical with the nitrogen atom, preferably having a five to six atom nucleus and including a second nitrogen atom or an oxygen atom such as morpholino, piperazino, pyrrolino, pyridino, pyrimidino, piperidino and the like.

Typical suitable tetronimides, pyronimides and amino hexose reductones are set out in Table B:

TABLE B 5-Pheny1-3 -hydroxy tetronimide HO C C OH CH-G C=NH 5-(4-Carboxyphenyl)-3-hydroxy tetronimide, 5-(3,4-Dimethoxyphenyl)-3-hydroxy tetronimide, 5-(n-Butyl)3-hydroxy tetronimide 5-(2-Furyl)-3-hydroxy tetronimide 5 -a-Furyl-3 ,4-dihydroxy-2-imino-2,5-dihydrofuran), and the like; 5,6-Diphenyl-3,4,5-trihydroxy-5,6-dihydro-pyronimide 5 ,6-Di-n-butyl-3 ,4,5-trihydroxy-5 ,6-dihydro-pyronimide,

5,6-Di-morpholino-3,4,5-trihydroxy-5,6-dihydropyronimide,

5,6-(2-Sulfophenyl)-3,4,5-trihydroxy-5,6-dihydropyronimide, and the like;

Dimethylamino hexose reductone Di-n-butylamino hexose reductone Di-n-hexylamino hexose reductone Morpholino hexose reductone Piperazino hexose reductone Pyrrolino hexose reductone Piperidino hexose reductone and the like.

The tetronimides and pyronimides such as mentioned above may be prepared by the methods described in British Pat. No. 782,304, Swiss Pat. No. 322,985, and in Helv. Chim. Acta, 39, 1780 (1956). The above, and still other 3-hydroxy tetronimides and 3,4,5-trihyd'roxy- 5,6-dihydro-pyronimides that are suitable, are disclosed in Salminen, U.S. Pat. No. 3,330,655, issued July 11, 1967.

The amino hexose reductones of the invention are derived from sugars, especially D-glucose, although other six carbon or hexose reducing sugars such as D- galactose, D-mannose, D-fructose, L-sorbose or the like can be used. A typical method for preparing the subject reductones comprises heating in a reaction medium substantially free of water a hexose reducing sugar and an aliphatic or cyclic secondary amine in the presence of an acidic reductone-forming catalytic agent such as phosphoric acid, boric acid, acetic acid, succinic acid or the like. The removal or three mole cules of water results during the formation of the subject amino hexose reductones. The mentioned reductones and other related suitable reductones and methods for preparing such are described in Hodges, U.S. Pat. No. 2,936,308.

Emulsions containing a methine dye of the type described above can be supersensitized with an azaindene, such as a triazaindene, a tetraazaindene or a pen taazaindene. Hydroxy and amino substituted azaindenes are especially useful. Representative useful azaindenes include those described in the following references:

Allen et al U.S. Pat. No. 2,735,769, Feb. 2l, 1956 Allen et al U.S. Pat. No. 2,743,181, April 24, 1956 Tinker et al U.S. Pat. No. 2,835,581, May 20, 1958 Reynolds U.S. Pat. No. 2,756,147, July 24, 1956 Carroll et al U.S. Pat. No. 2,743,180, Apr. 24, 1956 Zeitschrift fur Wiss, Phot. 47,2-28 (1952) Carroll et al U.S. Pat. No. 2,716,062, Aug. 23, 1955 Allen et al U.S. Pat. No. 2,772,164, Nov. 27, 1956 Allen et al U.S. Pat. No. 2,713,541, July 16, 1955 Tinker U.S. Pat. No. 2,852,375, Sept. 16, 1958 Carroll U.S. Pat. No. 2,743,180, Apr. 24, 1956 29 Fry U.S. Pat. No. 2,566,658-9, Sept. 4, 1951 Heimbach et al U.S. Pat. No. 2,444,605-7, July 6,

1948 Heimbach et al U.S. Pat. No. 2,449,225-6, Sept. 14,

1948 Especially useful tctrazaindenes include those having the following formula:

Ruig gg'xmf eg/ w in which R is an alkyl group, e.g., methyl, ethyl, propyl, butyl, etc. Some particularly useful azaindenes are listed below:

4-hydroxy-2-,B-hydroxy-ethyl-6-methyl-l ,3,3a, 7-tetrazaindene -carbethoxy-4-hydroxyl ,3 ,3a,7-tetrazaindene 7-hydroxyl ,2,3 ,4,6-pentazaindene 2,4-dihydroxy-6-methyll ,3a,7-triazaindene 4-hydroxy-Z-y-hydroxypropyl-6-methyl-1,3 ,3a,7-tetrazaindene 4-hydroxy-2( 4-pyridyl )-6-methyl-l ,3 ,3a,7-tetrazaindene 4-hydroxy-6-methyll ,2,3,3a,7-pentazaindene 5-amino-2-(p-carboxyphenyl)-7-hydroxy-1,3 ,4,6-

pentazaindene 2,4-dihydroxy-6-methyl-1,3a,7-triazaindene 2,5-dimethyl7-hydroxy-l ,4,7a-triazaindene 5-amino-7-hydroxy-2-methyll ,4,7a-triazaindene 5-carboxy-4-hydroxy-l ,3 ,3a,7-tetrazaindene 1 ,2-bis( 4-hydroxy-6-methyll ,3,3a,7-tetrazaindene- 5-yl)ethane 1,2,3 ,4-tetrakis(4-hydroxy-6-methyl-1,3 ,3a,7-tetraazaindene-2-yl)butane 2-amino-5-carboxy-4-hydroxyl ,3 ,3a,7-tetrazaindene 4-hydroxy-6-methyl-l ,3 ,3a,7-tetrazaindene As noted above, azaindenes function as supersensi-- tizer in emulsions containing various methine dyes. In some emulsions, the azaindene is advantageously used in combination with reducing agent, or preferably sulfonated organic compound supersensitizer, to produce emulsions having the best overall characteristics in terms of inherent emulsion speed, sensitized speed, low fog and storage stability.

According to the invention, one or more of the sulfonated organic compounds or one or more of the azaindenes or one or more of the reducing agents, and one or more of the methine dyes, are added separately or together to light-sensitive photographic silver halide emulsions to supersensitize the emulsions. Particularly good results are frequently obtained when both sulfonated organic compound and reducing agent are employed. In some emulsions, excellent results are obtained with the combination of an azaindene with a sulfonated organic compound supersensitizer. In other instances, it is desirable to supersensitize emulsions with methine dye and sulfonated organic compound, reducing agent and azaindene. The dyes most effectively supersensitized with the compounds described above are the cyanines, particularly the carbocyanine, dicarbocyanine and tricarbocyanine dyes. The enamine tricarbocyanine dyes described herein, such as those of Formula II above, are particularly effective when used with supersensitizer.

The optimum concentration of methine dye and supersensitizer can be determined in a manner well known to those skilled in the art by measuring the sensitivity of test portions of the same emulsion, each por- 5 tion containing a different concentration of dye and supersensitizer or mixture of supersensitizers. As a general guideline, good results are obtained with about 100 to 2,000 mg dye per mole of silver and about 25 to 2,000 mg and preferably 50 to 1,000 mg per mole of silver of the sulfonated organic supersensitizer.

The silver halide emulsions described herein can be unwashed or washed to remove soluble salts. In the latter case the soluble salts can be removed by chill-setting and leaching or the emulsion can be coagulation washed, e.g., by the procedures described in Hewitson et al U.S. Pat. No. 2,618,556; Yutzy et al U.S. Pat. No. 2,614,928; Yackel U.S. Pat. No. 2,565,418; I-Iart et al U.S. Pat. No. 3,241,969; and Waller et a1 U.S. pat. No. 2,489,341.

The noble metal and sulfur sensitizers can be added to the emulsion by conventional procedures, such as those described by Smith et al in U.S. Pat. No. 2,448,060 issued Aug. 31, 1948. Generally, the sensitizers are added at the completion of Ostwald ripening and prior to final digestion.

The silver halide emulsions of this invention can contain speed increasing compounds such as polyalkylene glycols, cationic surface active agents and thioethers or combinations of these as described in Piper U.S. Pat. No. 2,886,437; Chechak U.S. Pat. No. 3,046,134; Carroll et al U.S. Pat. No. 2,944,900; and Goffe U.S. Pat. No. 3,294,540.

Silver halide emulsions of this invention can be protected against the production of fog and can be stabilized against loss of sensitivity during keeping. Suitable antifoggants and stabilizers, which can be used alone or in combination, include the thiazolium salts described in Staud U.S. Pat. No. 2,131,038 and Allen U.S. Pat. No. 2,694,7l6;the azaindenes described in Piper U.S. Pat. No. 2,886,437 and Heimbach U.S. Pat. No. 2,444,605; the mercury salts described in Allen U.S. Pat. No. 2,728,663; the urazoles described in Anderson U.S. Pat. No. 3,287,135; the sulfocatechols described 45 in Kennard U.S. Pat. No. 3,236,652; the oximes described in Carroll et al British Pat. No. 623,448; nitron;

nitroindazoles; the me'rcaptotetrazoles described in Kendall etal U.S. Pat. No. 2,403,927, Kennard et al U.S. Pat. No. 3,266,897 and Luckey et a1 U.S. Pat. No. 50 3,397,987; the polyvalent metal salts described in Jones U.S. Pat. No. 2,839,405; the thiuronium salts described in Herz U.S. Pat. No. 3,220,839; and the palladium, platinum and gold salts described in Trivelli U.S.

Pat. No. 2,556,263 and Damschroder U.S. Pat. No. 2,597,915.

Photographic elements including emulsions prepared in accordance with this invention can contain incorporated developing agents such as hydroquinones, catechols, aminophenols, 3-pyrazolidones, ascorbic acid and its derivatives, reductones and phenylenediamines, or combinations of developing agents. The developing agents can be in a silver halide emulsion and/or in another suitable location in the photographic element. The developing agents can be added from suitable solvents or in the form of dispersions as described in Yackel U.S. Pat. No. 2,592,368 and Dunn et a1 French Pat. No. 1,505,778.

Silver halide grains sensitized in accordance with the invention can be dispersed in colloids that can be hardened by various organic or inorganic hardeners, alone or in combination, such as the aldehydes, and blocked aldehydes, ketones, carboxylic and carbonic acid derivatives, sulfonate esters, sulfonyl halides and vinyl sulfones, active halogen compounds, epoxy compounds, aziridines, active olefins, isocyanates, carbodiimides, mixed function hardeners and polymeric hardeners such as oxidized polysaccharides, e.g., dialdehyde starch, oxyguargum etc.

Photographic emulsions sensitized in accordance with this invention can contain various colloids alone or in combination as vehicles or binding agents. Suitable hydrophilic materials include both naturallyoccurring substances such as proteins, for example, gelatin, gelatin derivatives, cellulose derivatives, polysaccharides such as dextran, gum arabic and the like; and synthetic polymeric substances such as water soluble polyvinyl compounds, e.g., poly(vinylpyrrolidone) acrylamide polymers or other synthetic polymeric compounds such as dispersed vinyl compounds in latex form, and particularly those which increase the dimensional stability of the photographic materials. Suitable synthetic polymers include those described, for example, in U.S. Pat. No. 3,142,568 of Nottorf, issued July 28, 1964; U.S. Pat. No. 3,193,386 ofWhite, issued July 6, 1965; U.S. Pat. No. 3,062,674 of Hcuck, Smith and Yudelson, issued Nov. 6, 1962; U.S. Pat. No. 3,220,844 of Houck, Smith and Yudelson, issued Nov. 30, 1965; Ream and Fowler U.S. Pat. No. 3,287,289, issued Nov. 22, 1966; and Dykstra U.S. Pat. No. 3,41 1,91 1; particularly effective are those waterinsoluble polymers of alkyl acrylates and methacrylates, acrylic acid, sulfoalkyl acrylates or methacrylates, those which have cross linking sites which facilitate hardening or curing and those having recurring sulfobetaine units as described in Canadian Pat. No. 774,054.

Emulsions supersensitized in accordance with this invention can be used in photographic elements which contain antistatic or conducting layers, such as layers that comprise soluble salts, e.g. chlorides, nitrates, etc., evaporated metal layers, ionic polymers such as those described in Minsk U.S. Pat. Nos. 2,861,056 and 3,206,312 or insoluble inorganic salts as those described in Trevoy U.S. Pat. No. 3,428,451.

Photographic emulsions containing the supersensitizing combinations of the invention can be coated on a wide variety of supports. Typical supports include cellulose nitrate film, cellulose ester film, poly(vinyl acetal) film, polystyrene film, poly(ethylene terephthalate) film, polycarbonate film and related films or resinous materials, as well as a glass, paper, metal and the like. Typically, a flexible support is employed, especially a paper support, which can be partially acetylated or coated with baryta and/or an alpha-olefin polymer, particularly a polymer of an alpha-olefin containing two to carbon atoms such as polyethylene, polypropylene, ethylenebutene copolymers and the like.

Sensitized emulsions of the invention can contain plasticizers and lubricants such as polyalcohols, e.g., glycerin and diols of the type described in Milton U.S.

Pat. No. 2,960,404; fatty acids or ester such as those described in Robijns U.S. Pat. No. 2,588,765 and Duane U.S. Pat. No. 3,121,060; and silicone resins such as those described in DuPont British Pat. No. 955,061.

The photographic emulsions sensitized as described herein can contain surfactants such as saponin, anionic compounds such as the alkyl aryl sulfonates described in Baldsiefen U.S. Pat. No. 2,600,831 and amphoteric compounds such as those described in Ben-Ezra U.S. Pat. No. 3,133,816.

Photographic elements containing emulsion layers sensitized as described herein can contain matting agents such as starch, titanium dioxide, zinc oxide, silica,polymeric beads including beads of the type described in Jelley et a1 U.S. Pat. No. 2,992,101 and Lynn U.S. Pat. No. 2,701,245.

Sensitized silver halide emulsions of the invention can be utilized in photographic elements which contain brightening agents including stilbene, triazine, oxazole and coumarin brightening agents. Water soluble brightening agents can be used such as those described in A1- bers et a] German Pat. No. 972,067 and McFall et al U.S. Pat. No. 2,933,390 or dispersions of brighteners can be used such as those described in Jansen German Pat. No. 1,150,274 and Oeticker et al U.S. Pat. No. 3,406,070.

Photographic elements containing emulsion layers sensitized by the invention can be used in photographic elements which contain light absorbing materials and filter dyes such as those described in Sawdey U.S. Pat. No. 3,253,921; Gaspar U.S. Pat. No. 2,274,782; Carroll et a1 U.S. Pat. No. 2,527,583 and Van Campen U.S. Pat. No. 2,956,879. If desired, the dyes can be mordanted, for example, as described in Milton and Jones U.S. Pat. No. 3,282,699.

The sensitizing dyes (and other emulsion addenda) can be added to the photographic emulsions from water solutions or suitable organic solvent solutions, for example with the procedure described in Collins et a1 U.S. Pat. No. 2,912,343; Owens et al U.S. Pat. No. 3,342,605; Audran U.S. Pat. No. 2,996,287 or Johnson et a1 U.S. Pat. No. 3,425,835. The dyes can be dissolved separately or together, and the separate or combined solutions can be added to a silver halide emulsion, or a silver halide emulsion layer can be bathed in the solution of dye or dyes.

Photographic emulsions of this invention can be coated by various coating procedures including dip coating, air knife coating, curtain coating, or extrusion coating using hoppers of the type described in Beguin U.S. Pat. No. 2,681,294. If desired, two or more layers may be coated simultaneously by the procedures described in Russell U.S. Pat. No. 2,761,791 and Wynn British Pat. NO. 837,095.

Emulsions sensitized as described herein are useful in colloid transfer processes such as described in Yackel et al U.S. Pat. No. 2,716,059; silver salt diffusion transfer processes such as described in Rott U.S. Pat. No. 2,352,014, Land U.S. Pat. No. 2,543,181, Yackel U.S. Pat. No. 3,020,155 and Land U.S. Pat. No. 2,861,885; color image transfer processes such as described in R0- gers U.S. Pat. Nos. 3,087,817; 3,185,567; and 2,983,606; Weyerts U.S. Pat. No. 3,253,915, Whitmore et a1 U.S. Pat. Nos. 3,227,550; 3,227,551 and 3,227,552; and Land U.S. Pat. Nos. 3,415,644; 3,415,645; 3,415,646; and imbibition transfer processes as described in Minsk U.S. Pat. No. 2,882,156.

Silver halide emulsions containing the sensitizer combinations of this invention can be used in elements designed for color photography, for example, elements containing color-forming couplers such as those described in Frolich et al U.S. Pat. No. 2,376,679; Vittum et al U.S. Pat. No. 2,322,027; Fierke et a1 U.S. Pat. No. 2,801,171; Godowsky U.S. Pat. No. 2,698,794; Barr et al U.S. Pat. No. 3,227,554 and Graham U.S. Pat. No. 3,046,129; or elements to be developed in solutions containing color-forming couplers such as those described in Mannes and Godowsky U.S. Pat. No.

2,252,718; Carroll et al U.S. Pat. No. 2,592,243 and Schwan U.S. Pat. No. 2,950,970. Exposed photographic emulsions of this invention can be processed by various methods including processing in alkaline solutions containing conventional developing agents such as hydroquinones, catechols, aminophenols, 3-pyrazolidones, phenylenediamines, ascorbic acid derivatives, hydroxylamines, hydrazines and the like; web processing such as described in Tregillus et al U.S. Pat. No. 3,179,517; stabilization processing as described in Yackel et al Stabilization Processing of Films and Papers, BSA Journal, Vol. 16B, August, 1950; monobath processing as described in Levy Combined Development and Fixation of Photographic Images with Monobaths, P h r. Sci. and Eng, Vol. 2, No. 3, October, 1958, and Barnes et al U.S. Pat. No. 3,392,019. If desired, the photographic emulsions of this invention can be processed in hardening developers such as those described in Allen et a1 U.S. Pat. No. 3,232,761; in roller transport processors such as those described in Russell U.S. Pat. No. 3,025,779; or by surface application processing as described in Example 3 of Kitze U.S. Pat. No. 3,418,132.

The silver halide emulsions sensitized by this invention can be used for making lithographic printing plates such as by the colloid transfer of undeveloped and unhardened areas of an exposed and developed emulsion to a suitable support as described in Clark et a1 U.S. Pat. No. 2,763,553; to provide a relief image as described in Woodward U.S. Pat. No. 3,402,045 or Spencer U.S. Pat. No. 3,053,658; to prepare a relief printing plate as described in Baxter et al U.S. Pat. No. 3,271,150.

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

EXAMPLES l-8 A set of examples are prepared with four variables in order to illustrate optimum conditions of noble metal and sulfur sensitization of a very time grain gelatino silver iodobromide (2.5 mole percent iodide) Lippmann emulsion of 0.05 pm grain size. The four variables are l level of noble metal sensitization, (2) level of sulfur sensitization, (3) length of time of the chemical sensitization at 65 C, and (4) the level of Dye A with which the emulsion was spectrally sensitized before coating (see structure and name below). Each emulsion is exposed for seconds to a tungsten 500W light source in an Eastman 1B Sensitometer and developed for 4 minutes in Kodak D-l9 developer. The coatings are made at approximately 250 mg silver and 600 mg gelatin per square foot on a cellulose acetate support. The results are shown in Table I below.

Example 1 shows the sensitivity of the primitive emulsion without chemical or spectral sensitization. Example 2 shows amarked decrease in speed upon gold and sulfur sensitization at levels in a range customarily used in the art. Upon spectral sensitization (Example 3), a notable speed increase is observed. In Example 4 a substantially higher level of gold sensitization compared with Example 3 gives a relative speed increase from 100 to 363, accompanied by a small increase in fog. An intermediate but still high level of gold sensitization is indicated in Examples 5 and 6 with lower levels of sulfur sensitization and dye. The relative speeds of these emulsions are high but not as high as in Example 4. Example 7 shows that an increase in sulfur sensitization actually causes a decrease in speed when compared to Example 6. The higher the gold level, the greater the speed. The speed generally varies inversely with the sulfur and the dye levels. Example 8 compared with Example 3 shows little change in speed when a lower level of dye was used. However, the speed drops substantially when the dye is omitted.

Dye A Anhydro-3,9-diethyl-5,5 -dimethoxy-3 -(3- sulfopropyl)thiacarbocyanine hydroxide, the red sensitizer used in the examples above.

EXAMPLE 9 A series of gelatino silver iodobromide Lippmann emulsions with varying iodide content from O. to 18.8 mole percent is prepared. The grain size decreases as the iodide content increases. The emulsions are treated in three ways (A) given no further chemical sensitization, (B) chemically sensitized with 176 mg. sodium thiosulfate (23 mg. sulfur) plus 88 mg. potassium tetrachlorate (42 mg. gold) in the range 0 to 10 minutes at C, and (C) chemically sensitized with 30 mg. sodium thiosulfate (3.9 mg. sulfur) plus 300 mg. potassium tetrachloraurate 144 mg. gold) in the range of 0 to 10 minutes at 65 C. (Little change is noted within the 0 to 10 minutes time range.) All are coated with 300 mg. of Dye B per mole of silver. The results of photographic tests (conducted as in Examples l-8) are given in Table II. The above concentrations are given in mg. per mole silver 35 H N c H 2 Z 5 8 H2 H D Dye B -3-Ethy1-5-[2-(3-pyrrolin-1-yl)-Lcyclopentenylmethylene]rhodanine.

TABLE 11 The relative speeds are based on the same scale as Table 1.

The data show that the speed effects of the high gold sensitization C persist through a wide range of iodide content of the silver iodobromide emulsion. Much smaller speed gains are obtained from the high sulfur and lower gold sensitization (Treatment B). Although some speed loss is noted in going to higher iodide content, the bulk of the effect is attributable to the decreasing grain size of the emulsion. Results generally similar to those in Table II are obtained when the noble metal sensitizer is an equivalent amount of gold, platinum or palladium added. e.g., in the form of potassium iodoaurate, auric trichloride, potassium aurithiocyanate, a compound of the formula:

ammonium chloropalladate, sodium chloroplatinate, ammonium chlororuthenate or ammonium chloroiridate. Also, generally similar results to those in Table II are obtained when the sulfur sensitizer is added in an equivalent amount of a sulfur sensitizer other than sodium thiosulfate, such as thiourea, thiosinamine. Likewise, results generally similar to those in Table II are obtained when the various methine dyes referred to herein are substituted for dye B.

A series of Lippmann gelatin silver bromoiodide (2.5 mole percent of the halide being iodide) emulsions are prepared and coated on a cellulose acetate support at a concentration of 250 mg. silver per square foot and 1,041 mg. gelatin per square foot. The emulsions are chemically sensitized with potassium tetrachloroaurate and sodium thiosulfate, with minute digestion at 65 C after addition of the chemical sensitizers. Various dyes, identified in Table T below, are added to the emulsions, which have the grain size and contain the concentration of chemical sensitizer given in the following tables. Supersensitzer A is 4,4-bis[4,6-bis-ochloroanilino-s-triazin-Z-yl amino]-2,2 "stilbenedisul- TABLE III Silver halide grain size .09 micron; 300 mg. potassium tetrachloroaurate per mole of silver (about 150 mg. gold per mole of silver) and 30 mg. sodium thiosulfate (about 4 mg. sulfur per mole of silver): Mg. dye Relative Sensi- 1 per mole Superblue zation Dye of silver sensitizer speed Fog max.

Con-

trol 8.0 .07

1 450 200 .08 535 2 569 60 .06 495 3 818 A 182 .16 525 4 847 S5 .06 495 5 510 200 .06 490 Control 6.5 .08

1 600 200 .08 540 6 515 A 117 .10 540 7 810 A 174 .09 540 8 843 158 .08 565 8 562 148 .08 565 9 548 .1 1 550 10 444 174 .08 535 1 1 556 A 14 .06 12 663 A 200 .08 525 13 541 A 129 .09 525 14 569 A 158 .08 570 15 366 A 105 .08 540 1 16 100 A+B 302 .12 Pan 17 125 Control 6.2 08

1 450 200 .07 540 18 543 .08 525 6 343 A+B 117 .08 535 19 645 83 .06 525 20 690 71 .09 545 7 540 234 .07 535 8 562 174 .06 535 Control 5.9 .06

1 450 200 .06 540 21 794 100 .07 515 22 820 58 .08 525 23 480 A 43 .08 525 24 714 129 .08 525 9 41 1 A 110 .10 545 25 246 A 71 .06 530 10 296 245 .08 535 26 437 A 35 .08 Control 2.2 .02 17 300 93 .12 715 17 300 A+B 162 .11 715 16 300 A+B 170 .12 640 27 300 A+B .22 720 28 287 A+B .20 720 29 333 A+B 162 .14 720 30 318 A+B 170 .20 710 31 265 A+B 170 .24 700 32 189 200 .08 565 Control l 4 .08 17 300 A+B 170 14 720 Control 33 300 A 132 v06 690 34 300 A 170 .06 640 17 300 A 144 .10 715 35 291 A 170 .08 700 36 300 93 .18 720 16 200 263 .10 635 TABLE W Silver halide grain size .09 micron; 200 mg. potassium tetrachloroaurate per mole of silver (about 100 mg. gold per mole of silver) and 20 mg. sodium thiosulfate per mole of silver (about 2.6 mg.

sulfur per mole of silver):

Mg. dye Relative Sensiper mole Superblue tization Dye of silver sensitizer speed Fog maximum Control 4.0 .06

TABLE V Silver halide grain size .05 micron; 320 mg. potassium tetrachloroaurate per mole of silver (about 160 mg. gold per mole of silver) and 32 mg. sodium thiosulfate per mole of silver (about 4 mg.

sulfur per mole of silver):

Silver halide grain size .05 micron; 300 mg. potassium tetrachloroaurate per mole of silver (about 150 mg. gold per mole of silver) and 30 mg. sodium thiosulfate per mole of silver (about 4 mg.

sulfur per mole of silver):

Mg. dye Relative Sensitiper mole Superblue v zation Dye of silver sensitizer speed Fog maximum Control (no dye) 15 0.06 32 575 200 0.08 565 41 S I56 0.08 640 42 500 71 .012 690 43 500 I20 0.08 640 TABLE T Dye No. Dye Name 1 3-Allyl-5-[5 ,5-dimethyl-3-(3-pyrrolinl -yl)-2- cyclohexenylidene]rhodanine 2 I 5,6Dichlorol ,3diethyl-2-benzim idazolinylidene) ethy1idene]- 1 -ethyl-2-thiobarbituric acid 3 3-Ethyl-5-[(3-ethyl-Z-benzothiazolinylidene)-ethylidene]- 2-(2-thiazolyl)imino-4-imidaz0lidinone 4 l Z-Diethylaminoethyl )-5-[ 3-ethyl-2-benzoxazolinylidene)ethylidene]-3-phenyl-2thiobarbituric acid 5 3,6;3,8-Di-(trimethylene)triazolinocarbocyanine perchlorate 6 3-Ethyl-2-[ 4-( 3-pyrrolin-' l -yl l ,3-pentadienyl]benzothiazolium perchlorate 7 5,6-Dichloro-l,3-diethyl-3-[2-( l-pyrrolidinyU-ethyllbenzimidazolo-oxacarbocyanine iodide 8 l, l ',3,3'-Tetraethyl-5,5 '-bis(trifluoromethyl )-ben zimidazolocarbocyanine iodide 9 2-[4 1-Piperidyl)-A"-butadienyl]-fi-naphthothiazole ethiodide l0 3-Ethyl-5(3-methyl-2-thiazolinylidene-ethylidene)- l phenyl-2-thiohydantoin l l l-[4-(4-morpholyl )-A'-butadienyl lbenzothiazole ethiodide l2 3-Ethyl-5-l 3-methyl-Z-thiazolidinylidene)ethylidene]-l (2-morpholinoethyl)-Z-thiohydantoin r l 3 l-(2-Diethylaminoethyl)-5-{ (3-methyl-2-thiazolidinylidene)ethylidenei -3-phenyl-2-thiohydantoin 14 3-Ethyl-5-{ 3-(4-sulfobutyl-2(3H)-benzoxazolylidene)]- ethylidene}rhodanine l5 3'Ethyl-5 [7-( l-piperidyl)allylidenelrhodanine l6 3Ethyl-2-{2-[2,3,4,4a,5,6hexahydro-7-( l-pyr- TABLE T-continued Dye No. Dye Name rolidinyl)-l-naphthyl]vinyl}benzoxazolium iodide l7 3,3 -Diethyl-6,6 '-dimethoxythiadicarbocyanine p-toluenesulfonate l8 3-Ethyl-2-[4-( l ,2,5,6tetrahydrol -pyridyl )3,4-trimethylene-l ,3-butadienyl]benzoxazolium perchlorate l9 2-[6-Ethoxycarbonyl-3-( l-pyrrolidinyl) 2-cyclohexenylidenelmethyl-3-ethylbenzothiazolium perchlorate 20 2,3'-Bis(3,3-diethoxypropyl) 9-ethyl5,5'-diphenylox acarbocyanine bromide 21 2,2 Diethyloxacarbocyanine iodide 22 2,2-Diethyl-8-methyloxacarbocyanine iodide 23 4,4'-Dichloro-2,2,8-triethyloxacarbocyanine iodide 24 3,3-Diethyl-4,4-dimethyl-4'.5'-benzoxazolino-thiacar bocyanine fluoborate 25 3-Ethyl-5-[(3-ethyl-2-oxazolidinylidene)- ethylidene]rhodanine 26 4-[ I -Ethyl-2( l )-B-naphthothiazolylidene)isopropylidene] -3-methyll -(p sulfophenyl)-5-pyrazolone 27 3,3'-Diethyl-l0, l 2-ethylene-l l-(4 phenyll -piperazinyloxatricarbocyanine perchlorate 28 3,3'-Diethyl-l0, l 2-ethylene-l l-( l,2 3,4-tetrahydro-2- isoquinolyl)oxatricarbocyanine perchlorate 29 3,3'-Diethyl-l0, l 2ethylenel l-[4-( 3phenylpropyl piperidinolthiatricarboeyanine perchlorate 30 3,3-Diethyl-l0, l 2-ethylene-l l-[4-( 3-phenylpropyl)- piperidinoloxatricarbocyanine perchlorate 3i 3,3-Diethyll0, l 2ethylene-l l-( l ,2,5,6tetrahydro-l pyridyl)oxatricarbocyanine perchlorate 32 3-Ethyl-5-[2-(3-pyrrolinl -yl)- l -cyclopentenylmethylene] rhodanine 33 3-Ethyl-5-[ l-indolinyl)-5,S-dimethyl-2-cyclohexenl ylidene]ethylidene rhodanine 34 Anhydro-3-methyl-9-(2-pyrrolyl)-3-(3-sulfopropyl)- 4;5;4',5'-dibenzothiacarbocyanine hydroxide 35 3,3'-Diethyl-7,7'-dimethoxythiadicarbocyanine iodide 36 2-[( l-Carboxymethyl-4-oxo-3-phenyl-2-thioxo-5- imidazolidenylidene)ethylidene] 3-ethyll-phenyl-S- l ,3,3-trimethyl-2-indolinylidene)ethylidene] -4- imidazolidinone 37 5{ 2-( l-Azetidinyl)- l -cyclopentenylmethylene] 3 ethylrhodanine 38 3-Ethyl-5-[ 3ethyl-2( 3 )-benzoxazolyidene )is0pr0pyli dene rhodanine 39 Anhydro-I-allyl5-chloro-3'-ethyl-5'-methoxy-3-(3-sul fopropyhbenzimidazolo-oxacarbocyanine hydroxide 40 3-Carboxymethyl-5[2(3-pyrrolin-l yl)-l-cyclopcntenylmethylenelrhodanine, sodium salt 41 3-Ethyl-5-[( 3-methyl-2thiazolidinylidene )ethylidene 1- 2 {3-methyl-2-thiazolidinylidene)-l-propenyl1-4-oxo-lphenyl2imidazolinium iodide 42 3-Ethyl-5-[(3-methyl-2-thiazolidinylidene)ethylidene1- 2-[ 3-ethyl-4-oxo-2-thioxo-5thiazolidinylidene ]-ethyli denell -phenyl-4-imidazolidinone ylidene )-4,4-dioxo-l ,l '-diphenyHmidazolinocarbocyanine perchlorate Silver halide emulsions sensitized as described herein are particularly useful in microelectronic manufacturing, e.g., solid state circuit production, and in the production of holograms. These materials are described, for example, in Kodak Data Book P-9, Kodak Films and Plates for Science and Industry, published by the Eastman Kodak Co., 1967. Emulsions employed for such purposes advantageously contain a high concentration of at least one removable and substantially photographically inert light absorbing dye, as described in Stevens British Pat. No. 1,139,062. Since these materials are generally exposed to a mercury vapor source which emits in the blue region of the spectrum at 405 nm and 436 nm and in the green region at 547 nm, it is desirable that the silver halide exhibit high sensitivity to all three line exposures. The use of absorbing dyes to reduce image spread and produce images of exceptionally high sharpness reduces the speed and contrast of these elements as described in Kodak British Pat. No. 1,139,062. It is, therefore, desirable to increase either or both blue and green speeds. The combination of a benzothiazolinylidene-thiooxazolidinedione blue sensitizer with the oxathiazolocarbocyanine green sensitizer described in Stevens British Pat. No. 1,139,062 gives increased blue sensitivity with little or no change in green sensitivity. An increased concentration of the

Claims (9)

1. A PHOTOGAPHIC SILVER HALIDE EMULSION COMPRISING LIGHTSENSITIVE SILVER HALIDE GRAINS HAVING AN AVERAGE GRAIN SIZE UP TO ABOUT .2 MICRON, SAID SILVER HALIDE GRAINS BEING SENSITIZED WITH THE COMBINATION OF A GOLD SENSITIZED AT A CONCENTRATION OF ABOUT 50 TO 200 MILLIGRAMS GOLD PER MOLE OF SILVER, AND A SULFUR SENSITIZER AT A WEIGHT RATIO OF SULFUR TO GOLD OF FROM 1:15 TO 1:17, AND, SAID SILVER HALIDE BEING SPECTRALLY SENSITIZED WITH A DYE HAVING ONE OF THE FOLLOWING FORMULAS:

2. A photographic silver halide emulsion comprising light-sensitive silver halide grains having an average grain size up to about .2 micron; said silver halide grains being sensitized with the combination of a gold sensitizer, at a concentration of about 50 to 200 milligrams gold per mole of silver, and a sulfur sensitizer at a weight ratio of sulfur to gold of from 1:15 to 1: 75; and, said silver halide being spectrally sensitized with a methine dye having the Following formula:

3. A light-sensitive photographic silver halide emulsion as defined in claim 2 wherein said dye is supersensitized with at least one supersensitizer selected from a polynuclear aromatic compound containing at least one sulfo group and a silver halide reducing agent.

4. A photographic silver halide emulsion comprising light-sensitive silver halide grains having an average grain size up to about .2 micron; said silver halide grains being sensitized with the combination of a gold sensitizer, at a concentration of about 50 to 200 milligrams gold per mole of silver, and a sulfur sensitizer at a weight ratio of sulfur to gold of from 1:15 to 1: 75; and, said silver halide being spectrally sensitized with a methine dye having the following formula:

5. A light-sensitive photographic silver halide emulsion as defined in claim 4 wherein said dye is supersensitized with at least one supersensitizer selected from a polynuclear aromatic compound containing at least one sulfo group and a silver halide reducing agent.

6. A photographic silver halide emulsion comprising light-sensitive silver halide grains having an average grain size up to about .2 micron; said silver halide grains being sensitized with the combination of a gold sensitizer, at a concentration of about 50 to 200 milligrams gold per mole of silver, and a sulfur sensitizer at a weight ratio of sulfur to gold of from 1:15 to 1: 75; and, said silver halide being spectrally sensitized with a methine dye having the following formula:

7. A light-sensitive photographic silver halide emulsion as defined in claim 6 wherein said dye is supersensitized with at least one supersensitizer selected from a polynuclear aromatic compound containing at least one sulfo group and a silver halide reducing agent.

8. A photographic silver halide emulsion comprising light-sensitive silver halide grains having an average grain size up to about .2 micron; said silver halide grains being sensitized with the combination of a gold sensitizer, at a concentration of about 50 to 200 milligrams gold per mole of silver, and a sulfur sensitizer at a weight ratio of sulfur to gold of from 1:15 to 1: 75; and, said silver halide being spectrally sensitized with a methine dye having the following formula:

9. A light-sensitive photographic silver halide emulsion as defined in claim 8 wherein said dye is supersensitized with at least one supersensitizer selected from a polynuclear aromatic compound containing at least one sulfo group and a silver halide reducing agent.