Example 25.@3-ethyl-5- E (3-ethyl-2(3) -benzo-, thiazolylidene) -a- ethylet77,ylidenel.-2- (3-p-hydroxy- p- ethoxy- p- ethoxyethyl-4- axo-2- t hiono-5-thiazolidylidene) -4- thiazolidone . a5,oeiwherein R and Ri each represents an aryl grotili, Z and Zi each represents the nonmetallic atoms necessary to complete a heterocyclic nucleus of the benzothiazole series, and X represents an S\ OC-N-C2H5 00-NCH2CII20CH2CH20CH2CH20H C=CH-C=@ @@@ol @s \ s 21:15 .A mixture of 1.9 g. (I mol.) of 3-etbyl-5-[(3- 10 anion, and at least one complex merocyanine dye ethyl- 2 (3) - benzothiazolylidene) - aethylethyli - selected from those represented by the following denelrhodanine and 1.9 g. (I mol. plus 100% excess) of methyl p-toluenesulfonate were heated togetb-er for one hour in an oil bath at 140-1500 C. The cake of crystals was crushed 15 i.,ader acetone and the suspension was filtered. The crude addition prodlict, thus obtained, 1.33 g. (I mol.) of crude 3-(p-hydroxy-g-ethoxy-,a ethoxyethyl)rhodanine and 0.5 g. (I mol.) of triethylamine in 25 ml. of absolute ethyl alcohol 20 were heated together at the refiuxing temperature for 10 minutes. After chillin,-, the dye was washed on 'the L-ilter with methyl alcohol. The yield of dye was 60% crude and 7% after two recrystallizations from acetone. The dark green 25 crystals had melting point 180-183' C. with de_ composition. The 3- (p-hydroxy-,3-ethoxy-,e-ethoxyethyl) rhodanine used in the above example was prepared in the same manner as the 3-p-methoxy30 ethylrhodanine of Example 21 above, except that p-hydroxy-p-ethoxy-p-ethoxyethylamine was uscd instead of p-methoxyethylamiie. Although the oily layer of the 3- (p-hydroxy-p-ethoxy-pethoxyethyl)rhodanine was insoluble in benzene, 35 a mixture of the two was heated on the steam bath, under reduced pressure, first to dry the oily layer and then to remove the benzene. The residue of 8.8 g. of pale yellow oil was used without fi-irther purification. 40 The 3-ethyl-5-[(3-ethyl-2(3)-benzothiazolylidene)-a-ethylethylidenelrhodanine used in Example 25 was prepared as follows: A mixture of 44.4 g. (1 mol.) of 3-ethyl-2-thiopropionylmethylenebenzothiazoline and 66.0 g. 45 (1 mol. plus 100% excess) of methyl p-toluenesulfonate was heated at the temperature of the steam bath for 2 hours. The crude reaction mixture was washed with absolute ether. The addition product, 28.8 g. (I mol.) of 3-ethylrhoda50 nine and 17 ' 9 g. (I mol.) of triethylamine in 400 ml. of absolute ethyl alcohol were heated together at the refluxing temperature for 30 minutes. After chilling, the dYe was collected on a filter and washed with methyl alcohol. A second por55 tion of dye was isolated from the filtrate by treating it with water. The yield of dye, thus obtained, was 35%. The above examples are merely representative of the methods which can be used to prepare 60 the complex merocyanine dyes useful in practicing my invention, it being understood that other dyes represented by Forinula TT can b, prepared in like manner. What I claim as my invention and desire se(;5 cured by Letters Patent of the United States is11. A photographic silver halide emulsion sensitized with a supersensitizing combination of at least one diaryloxythiacarbocyanine dye selected from those represented by the following gen70 eral formula: C 11, I I z -N-C=C-CH=0-6@@T-CH@ R ORI x 75 general formula: 0 11 -Zi- O=C-N-R3 C-N-RI Rg-N(-L@L) C'- =s s s wherein R2, R3, and R4 each represents an alkyl group, L represents a methine group, d and n each represents a positive integer of from I to 2, and Z2 represents the nonmetallic atoms necessary to complete a heterocyclic nucleus selected from the group consisting of those of the benzothiazole series, those of the a-naphthothiazole series, those of the 6- naphthothiazole series, those of the benzoxazole series, and those of the quinoline series. 2. A photogranhic gelatino-silver halide developing-out' emulsion sensitized with a supersensitizing combination of at least one diar yloxythiacorbocyanine dye selected from those represented by the following general formula: Izil CH,g @R 10 R, Ix wherein R and Ri each represents an aryl group, Z and Zi each represents the nonmetallic atonis necessary to complete a heterocyclic nucleus of the beiizothiazole series, and X represents an anion, and at least one complex merocyanine dye selected from those represented by the following general formula: 0 11 Z2 O=C-N-R3 C-N-R4 - --- I I s wherein R2, R3, and R4 each represents an alkyl group, L represents a methine group, d and n each represents a positive integer of from 1 to 2, and Z2 represents the nonnletallic ator@,is necessary to complete a heterocyclic iiucleus selected from the group consisting of those of the benzothiazole series, those of the a-naphthothiazole series, those of the pnaphthothiazole series, those of the benzoxazole series, and those of the quinoline series. 3. A photographic gelatino-silver-bromiodide developing-out emulsion sensitized with a supersensitizing combination of at least one diaryloxythiacarbocyanine dye selected from those represented by the following general formula: z zi OR OR, x wherein R and Ri each represents an aryl group, Z and Zi each represents the nonrnetallic atoms necessary to complete a heterocyclic nucleus of the benzothiazole series, and X represents an anion. and at least one complex merocyanine dye

131 selected frbm those represented by the following general formula: 0 1 Z2 O=C----N-R3 b-N-R, P. 8 wherein R2, R3,, and R4@ each represents an alkyl@ gi,oup, L represents a methine groiip; d and n each represe-nts a positive integer of from. I to 2, and@ Z2 repi.-esents the nonmetallic atonis necessary to complete a heterocyclic nueleus selected from the group consisting of thosedf the benzothiazole seriesi thos.e of the a-naphthothiazole series, tho.5e: of the P,-naphthothiazole series, and those. of the benzoxazole series,, and. those of the quinoline series@ 4. A photographic silver halide developing-out emulsion sensitized with@ a supersensitizing combinatiori of at least one diary loxythiacarbocyanine dye selected from those represented by the following general formii1a. z Zi 1, CHS-N C=C-CH=C-C@N-CH3 1 @R @Ri x wherein@ R and R, each represents@ a mononuclear aroma.tic group of the benzene series, Z and Zi each represents the nbnmetallic atoms necessary to complete a heterocyclic nucleus of the benzothiazole series, and Xrepresents an anion, and at least@ one@ complex merocyanine dYe- selected from those representect by@ the following general formula: 0 -zi- O=C-N-R. 8-N-Ri @-S s s wherein R2 represents a member selected frorn the groupconsisting of a. methyl group, an ethyl grolip, and a;.,e-hydroxyethyl group, R3 and R4 each represents a member selected from the group consisting of a methyl group, an ethyl group, a n-heptyl, group@ a p@- methoxyethyl groupi a carbethoxymethyl group,@ and a p-hydroxy-g-ethoxyp-ethoxyethyl group, L repxesents a. methine group, d and@ n each represents a, positive integqr of from I to 2, and Z@ represents the@ nonmetallic atoms necessary to complete a@ heterocyclic nu cleus selected from the group consistin.g of those of the benzothiazole series, those of the a-naphthothiazole series, those of the p-naphthothiazole series, those of the benzoxazole series, and those of the quinoline series; 5. A photographic silver halide developing -Out emulsion sensitized with a supersensitizing combination of at least one diaryloxythiacarbocyanine dye selected from those represented by the following general formula: Z, Zi CH,l@---@C--C-CH=C-C @N-CHs I OR ORi x wherein R and Ri each represents a mononuclear aromatic group of the benzene series, Z and Zi each represents the nonmetallic atoms necessary to complete a heterocyclic nucleus of the benzothiazole series, and X represents an anion, and 14" f roin.1 those: iepresented -by. the foUowing..- general foxinula:':. @O 0. Z2 RI C--N-R. b-N-R, c C--S s s wherein R2 represents a member selected from the group, consisting.- of a methyl group, an ethyl 10 group., andr a 6@hydtoxyethyl@ 'group, R3, and R4 each represents a @member selected, from the group consisting of@ a methyl, group, an ethyl group@ a@n-heptyl grotip a p-methoxyethyli gtoup, a carbethonymethyl gr;up,l and a g-hydroxy-@p15 ethoxy-o-ethoxyethyl group, R' represents a member selected from the group consisting of a methyl gxoup, an ethyl group, and a phenyl group,, L. represen't,$ a methine group, d r-epresents a positive integer of from@ 1 to 2, and Z2 20 represent& the nonmetallic atoms- necessary to compiete@a@ heterocyclic nucleus selected from the@ group: consisting of those of the benzothiazole@ series@@ those of the a-naphthothiazole series, those of the 8-naphthothiazole series, those of the: 25 benzoxadole series;, a7ad those@ of the quinoline series, 6. A photographic@ silver halide@ developing-out emulsion sensitized with a supersensitizing combination of at least one diaryl oxythiacarbocy30 anine dye selected from those represented by the following general formula: I z .1 zil C-- Cn=C (5 \N-C]Ef@ 35 OR, ORI@ :P, wherein R and Ri@ each represents- a, mononuclear aromatic group of the benzene series; Z and@ Zi each represents the nonmetallic atoms. necessary to cbmplete a heterocyclic nucleus of the benzo40 thiazole series, and at least one complex merocyanine dye selected from those represented 4y the following general formula: 0 0 li45 Z2 RI c N.-R3 8-N-R4 C=S s s wherein R2 represents a meniber selected from .50 the group, consisting of a methyl group, an ethyl grouP, and a A-hydroxyethyl group, R3 and R4 each represeiats a member seleeted' from the'group consisting of a methyl group, an ethyl group, a -heptyl group, a p- et n m hoxyethyl group, a. car55 bethoxymethyl group,. and, a p-h@7droxy-g-ethoxy6-ethoxyethyl group, RI represents a member selected from the grOuP consisting of a hy(hogen atom, a methyl group, an ethyl group, and a phenyl group, d and n each represents a positive integer of from I to 2 and Z2 represents the non60 metallic atoms necessary to complete a heterocyclic nlicleus of the a-na,ohthothiazole series. 7@ A photographic silver halide developing-out emulsionsensitized with a supersensitizing,com65 bination of at least one diaryloxythiacarbocyanine dye. selected from those represented by the following general formula: z zi 70 OR OR@ X@ wherein R and Ri each represents a mononuclear aromatic group of the benzene series, z and Zi each represents the nonmetallic atoms@- necessary at least one complex merocyanine dye selected 75 to complete a heterocyclic nucleus of the benzo.

15 thiazole series, and at least one compiex m6rocyanine dye selected from those represented by the following general formula: 0 0 R' L@ 11 zi -N-R3 C-N-R4 R -N c (-CH= H) c c 8 s wherein R2, represents a member selected from the group consisting of a methyl group, an ethyl group, and a 3-hydroethyl group, R3 and R4 each represents a member selected from the group consisting of a methyl group, an ethyl group, a n-heptyl group, a p-methoxyethyl group, a carbethoxymethyl group, and a p-hydroxy-,3 -ethoxy,6-ethoxyethyl group, R' represents a member selected from the group consisting of a hydrogen atom, a methyl group, an ethyl group, and a phenyl group, d and n eachrepresents a positive integer of from 1 to 21 and Z2 represents the nonmetallic atoms necessary to c6mplete a heterocyclic nucleus of the p-naphthothiazole series. B. A photographic silver halide developing-out emulsion sensitized with a supersensitizing combination of at least one diaryl oxythiacarbo6yanine dye selected from those represented by the following general formiila: z Zi CH3-N-C=C-CH=C-C@N-CH3 @ R 'o R@ 'x wherein R and Ri each represents a mononuclear aromatic group of the benzene series, Z and Zi each represents the nonmetallic atoms necessary to complete a heterocyclic nucleus of the benzothiazole series, and at least one complex merocyanii'le dye selected from those represented by the following general formula: 0 0 11- 11 Z2 R' c N-R3 C-N-R4 I i -CH= '@) - Rrlc( C 'C@C C=S s s wherein R2 represents a member selected from the group consisting of a methyl group, an ethyl group, and a P-hydroethyl group, R3 and Ri each represents a member selected from the group consisting of a methyl group, an ethyl grouli, a neptyl group, a @-methoxyethyl group, a carbethoxymethyl group, and a 6-hydroxy-pe thoxy-,6-ethoxyethyl group, R' represents a member selected from the group consisting of a hydrogen atom, a methyl group, an ethyl group. and a phenyl group, d and n eachrepresents @ p . ositive integer of from 1 to 2, and Z2 represents the nonmetallic atoms necessary to complete a heterocyclic nucleus of the benzoxazole series . 9. A photographic silver halide developing-out emulsion sensitized with a supersensitizing combination of at least one diaryl oxythiacarbocyanine. dye selected from those represented by the following general formula: z zi CH,N-C=C-CH@C-C@N-C]13 I OR ORL x wherein R and Ri each represents a mononuclear aromatic group of the benzene series, Z and Zi each represents the nonmetallic atoms necessary to complete a heterocyclic nucleus of the benzothiazole series, and at least one complex merocyanine dye selected from those represented by the forowing general formula. 2,63b,gol0 ci 11 11 Z2 R' C-N-R3 C-N-RI RN(-CH=CH)d-l--C(=CH- IC).-@=@ @@@ C=S \S/ \S/ '5 wherein R2 represents a member selected from the group consisting of a methyl group, an ethyl group, and a B-hydroethyl group, R3 and P.4 each represents a member selected from the group 10 consisting of a methyl group, an ethyl group, an n-heptyligroup, a p-methoxyethyl group, a carbethoxyrnethyl group, and a p-hydroxy-p -ethoxyp-ethoxyethyl group, R' represents a member selected from the group consisting of a hydrogen 15 atom, a methyl group, an ethyl group, and a phenyl group, d and n each represents a positive integer of from I to 2, and Z2 represents the nonmetallic atoms necessary to complete a heterocyclic nucleus of the quinoline series. 20 1 0. A photographic silver halide developing-out emulsion sensitized with a supersensitizing combination of at least one diaryloxythiacarbocyanine dye selected from these represented by the following general formula: 25 z Zi CH3-NT-C=C-CH=C-c -cli@ I 0 R ORI x wherein R and Ri each represents a mononuclear 30 aromatic group of the benzene series, Z and Zi each represents the nonmetallic atoms necessary to complete a heterocyclic nucleus of the benzothiazole series, and at least one complex merocyanine dye selected from those represented 35 by the following general formula: 0 0 l@ 11 Z2 R, C-N-R3 C-N-RI R,N(-CH=CH c c c 40 s s wherein R2 represents a member selected from the groupconsisting of a methyl group, an ethyl group, and a p-hydroethyl group, R3 and R4 45 each represents a member selected from the group consisting of a methyl group, an ethyl group, an n-heptyl group, a 6-methoxyethyl group, a carbethoxymethyl group, and a,3-hydroxy-g-ethoxy6-ethoxyethyl group, R' represents a member 50 selected from the group consisting of a hydrogen atom, a methyl group, an ethyl group, and a phenyl group, d and n each represents a positive i integer of from 1 to 21 and Z2 represents the nonmetallic atoms necessary to complete a 55 heterocyclic nucleus of the benzothiazole series. 11. A photographic gelat-ino-silver-halide developing-out emulsion sensitized with a supersensitizing combination of 8,10-di (p-chlorophenoxy) - 3,3'- dimethylthiacarbocyanine p60 toluenesulfonate and 5-[(I-ethyl-2(i)-p-naphthothiazolyhdene) -a- ethylethylidenel - 3-pmethoxyethyl-2-(3-p-methoxyethyl -4- oxo-2- thiono-5-thiazo-lidylidene) -4-thiazolidone. 12. A Photographic gelatino-silver-halide de05 veloping-out emulsion sensitized with a supersensitizing combination of 3,3'- dimethyl-8,10- di(m-toloxy)thiacarbocyanine bromide and 5- L(3-p-hydroxyethyl -2(3) -a- naphthothiazolylidene) ethylidenel-3-p- methoxyethyl -2-(3-p70 methoxyethyl-4-oxo -2-; thiono -5- thiazolidylidene) -4-thiazolidone. 13. A photographic gelatino-silver-halide developing-out emulsion sensitized with a supersensitizing combination of 3 ,3'-dimethyl-8,10- 75 di(m-toloxy)thiacarbocyanine bromide and 2-

17 (3-carbethoxymethyl-4-oxo-2-thiono -5-thiazolidylidene)- -3-ethyl-5-[(l-ethyl-2(l)-pnaphthothiazolylidene) isopropylidene I -4-thiazolidone, 14. A photographic gelatino-silver-halide developing-out emulsion sensitized with a supei,sensitizing combination of 8,10-di(p-methoxyphenoxy) -3,3'- dimethylthiacarbocyanine bromide and 5-[(l-ethyl-2( l)-p-naphthothiazolylidene)2- ethylethylidenel-3-p- methbxyethyl-2(3-p-methoxyethyl -4- oxo-2-thiono-5- thiazolldylidene) -4-thiazolidone. is 15. A photographic gelatino-silver-halide developing-out emulsion sensitized with a supersensitizing combination of 3,31-dimethyl-8,1 0Ctiphenoxythiacarbocyanine bromide and 5-[(lethyl -2(l)-g- naphthothiazolylide ne)-a-ethylethylidenel-3-pmethoxy-ethyl -2-(3-p- methoxyethyl-4-oxo-2-thiono-5- @khiazolidylidene) - 4thiazolidone. BURT H. CILRROLL. 10 No references cited.

Patented Apr. 21, 1953 296359961 UN'ITED STATES PATENT OFFICE 2,635,961 SUPERSENSITIZATION OF PHOTOGRAPMC@ EMULSIONS WITH COMPLEX MEROCYANINE DYES Durt H. Carroll, Rochester.,, N. Y., assignor, to Eastinan Kodak Company, Rochester, N. Y'., a corporation of New Jersey Applicati,on March 1, 1952 Serial No. 274i445 . I 15 Claims. (Cl. 95-7) TbiE@ invention relates to photographic emuls@ons comprising certain, diarylox thiacarbo,Y eyaninq dyes, ond as @upersens tiz s therefor, i er eextain complex, merocyanine clyes. It is, l@nown, in the@ art of making photographic 5 Qmulsions that certain dyes of the eyanine class @alter the sensitivity of photographic emulsions of the gelatino-silver kind, when the dyes are in,corporated in the emulsions. It is also known that the sensitization produced by a given dye 10 varies. somewhat with the type of emulsion in which the dye is incorporated. FiLirthermore, the sensitization of a; given emulsion by a given dye, may be altered by varying conditions in the emulsion. For example, the sensitization may be 15 increased by increasing the silver ion concentration or. decrea iii @ S , g the hydrogen ion concentration (i. e'. increasing the alkalinit Y) or both. Thus, sensitization can be: increased by bathing plates, coated with a spectrally sensitized@ emul2@0 sion, in water or irx aqueous solutions. of ammonia.. Such a process of altering the sensitivity of a sensitized@ emulsion by increasing the silver ion concentration and/or by decreasing the hydrogen ion concentration is commonly called 25 "hypersensitization." Hypersensitized emulsions have generally poor keeping qualities. I have now found a new means of altering the sensitivi-ty in emulsions containing certain di,,iryloxythiacarbocyatline dyes of -i particular type. 30 ,Since@ the conditions in the emulsion, 1. e@ the ,hydrogen ion and/or the silver ion concentration undergo- little or no change in my new method, ]@ shall designate my new m.ethod as a kind of 'supersensitization. 35 It is, therefore, aii object of my ixivention to i?,rQv.ide. pboto,-raphic emulsions comprising certairk diaryloxythiacarbocyanine dyes and@, as supersensitizers therefor, certain complex merocyanine dyes@@ Anot'-Iier object is to provide a 40 p.rocess, for preparing these supersensitized emulsions. Other objects@ will become apparent from a, consideration of the following de@scription and examples. The complex merocyanine dyes useful in prac- 45 ti,eing my in:vention, have be.en previously propos.ed as sensitizers fo ,r photographic emulsions izi Broloker, V. S. Patent 2,544,629@, issued Novein bQr 2.3, 1948, beginning at line 62, col. 17. The 2 lnventioli., The uni.qup c'b4r@Lcter of, and unex.- Peet d behavior exli:ibited by my np-w sul?ersenstp ti;zing c@ombinations o@re hus evident. The diaryloxythiacarbocyaiii4e dyes usefu in practicing m inventioa co pris th,e 3,3' dtY methyl - 8,10 - (liaryloxythiai3arbocyanine dyp4 of Brooker and Wbito, U. S. Patent 2,478,366, issued August 9, 1949, These dyes share the characteristic of a sharp maximum, lyjng a;t a wavelength considerably lo,nger than that of the dye in the molecular state. Ftlrther, these dyes have unusually strong and sharp maxima of absorption and sensitivity, but when used alone, their usefulness is limited by low speeds, which M4y bp traced to low efficiency of energy trans.fer from, the dye to, the s,iiver halide grain, and to desensitization, (Spence and Carroll, "Jour. Phys. & Coll. Chem., vol. 52 (1940), p, 1090),., Tho .3,3'-diethyl-8,lQdiaryloxythiacarbocyaninQ dyes, 3,3' - diethyl - 8110 - diprylo:KyselenaQarbocyanine dyes, and 3,3' - di.ethyl - 8,10, - diaryloxyoxacarbqcyanine dyes have not given consistent. results which would justify their use for the purposes of this invention. The 3,31 - dimethyl - 8,10, - diaryloxythiacarboeyanine dyes uaeful in practicing my invention can advantageously be represented, by tlie. following general. formula: z Zi OR ORI wherein R and Ri each represents an aryl group, such as phenyl, o-I m-, and p-tolyl, o-, m-, and P-methoxyphenyl, o-I m-, and P-chlorophexlyl, 6-naphth 1, etc. (e. g. especially a mononuclear Y aromatic nucleus of@ the benzene ser.ies), Z and Zi each represents the nonmetallic atoms necessary@ to complete a heterocyclic nucleus of the benzothiazole series and X. represents an axiion, such as brornide, iodide, chloride, Perchlorate, thlocyanate, methylsulfate, ethylsulfate, benzenesulfonate, p-to luenesulfonate, etc. The dyes represente,d by Formula I can be prepared aer cording, to t e me I od d scribed in U S. Pate@xit b t]4 . e. en i n bove 2,478,366 m . to ed a The compipy@,mprqcyanine usefpl i:4 proqtici xig my invention can be represented by the fqllow1?arent merocyanine dyes, 4rom which the com- r)o ing general formu,la: i?li@x, dyes are, deriyed, liave no corresponding suil@ 0 per,se.@mttiz@@g effqcts. Nor do tlle complex Z 2 0-c-N-R3 8-N-Ri e.y,an@ne5 (alsq dqscribqcl tn @@,454,029) de@i.vqd fro,M the .5.amQ I?a ,r@ent merocyanine dyes eNM@t tbe@i$upQr,@5.Qns@tizin e@ffq4zt4shpwniii,,tbeiwallt 55 s@

3 wherein R2, R3, and R4 each represents an alkyl group, such as riethyl, ethyl, n-propyl, nbutyl, n-heptyl, p-hydroxyethyl, 8- carbethoxymethyl, ,6-methoxyethyl, 6 - ethoxyethyl, p - hydroxy-gethoxy-g-ethoxyethyl, etc., Lrepresents a methine group (i. e. - CRI=, wherein R' is a hydrogen atom, an alkyl group (methyl, ethyl, etc.) or an aryl group (phenyl, tolyl, etc.), etc.), d and n each represents a Dositive inteaer of from I to 2, ind Z2 represents the nonmetallic atoms necessary to complete a heterocyclic nucleus selected from those of the benzothiaole series, the a-naphthothiazole series, the 8-naphthothiazole series, the benzoxazole series, and the quinoline series. The complex mercyanine dyes represented by Formula II above can be prepared according to the method described in U. S. Patent 2,454,629, mentioned above. According to my Invention, I incorporate one or more of the diaryloxycarbocyanine dyes se@ .lected from those represented by Formula I above with one or more of the complex merocyanine dyes selected from those represented by Formula II above in a photographic emiilsion. My invention is particularly directed to the ordinarily employed gelatino-silver-halide emulsions. However, my supersensitizing combination can be em,ployed in silver halide emulsions in which the carrier is other than gelatin, e. g., a resinous substance or cellulosic material which has no deteriorating effect on the lightsensitive materials. The sensitizing dyes can be employed in various concentrations depending upon the effects ,desired. As is well known in the art, the sensitivity conferred upon an emulsion by a sensitizing dye does not increase proportionately to the concentration of the dye in the emulsion, but rather passes through a maximum as the concentration is increased. In practicing my invention, the individual sensitizing dyes are advantageously employed in a concentration somewhat, less than their optimum concentration (i. e ' the concentration at which the individual dyes give gre atestsensitivity). Ifeachofthedyesinthesupersensitizing combination is employed in itS OPtimum concentration, it is possible, in certain cases that the sensitization produced by the supersensitizing combination will have passed through amaximum. The optimum concentration of an individual sensitizing dye can be determined in a manner well known to those skilled in the art by measuring the sensitivity of a series of test portions of the same emulsion, each portion containing a different concentration of the sensitizing dye. The optimum concentration of my supersensitizing combinations can, of course, be readily determined in the same manner, by measuring the sensitivity of a series of test portions of the same emulsion, each portion containing different concentrations of the individual dyes in the combination. In deterrnining the optimum concentration for the supersensitizing combination, it is advantageous to employ, at first, concentrations of the individual dyes less than their optimum concentrations@ The concentrations of the individual dyes can then be increased until the optimum concentration of the supersensitizing combination is determined. Ordinarily the optimum or near optimum concentration of the diaryloxycarbocyanine dyes, selected from those represented by Formula I above which I employ in practicing my invention, is of the order of from 0.02 to 0.20 g. per mole of silver halide in the emulsion. 2,685,961 4 The complex merocyanine dyes selected from those represented by Formula H above are advantageously employed at concentrations on the order of 0.001 to 0.05 g. per mole of silver halide in the emulsion. Generally speaking, the ratio of concentration of the complex merocyanine dye (Formula II) to diaxyloxycarbocyanine dye (Formula I) can vary rather widely in my new combinations, e. g. from 10 1: 100 to 1: 2 (by weight) in many cases. The methods of incorporating sensitizing dyes in emulsions are well known to those suled in the art. In practicing my invention, the sensitizing dyes can be incorporated in the emulsions 15 separately or together. It is convenient to add the dyes separately in the form of solutions in appropriate solvents. MethanoI and ethanol, especially the former, have proven satisfactory as solvents for the dyes of Formula I which I em20 ploy, while acetone has proven satisfact ory as a solvent (with small amounts of ochlor6phenol to improve solubility in some instances) for the complek merocyanine dyes of F6rmula II. The dyes are advantageously incorporated in the fITiished, 25 washed emulsi6ns and should be uniformly I distributed throughout the emulsions. The following procedure is satisfactory: Stock solutions of the sensitizing dyes desired are prepared by dissolving the dyes in appropriate solvents as de30 scribed above. Then, to one liter of a flowable gelatino - silver - halide emlilsibn, the desired amounts of the stock solution of one of the dyes is slowly added, while stirring the emulsion. Stirring is continued until the dye is thoroughly 35 incorporated in the emulsion. Then the desired amount of the stock solution of the second dye is slowly added to the emulsion, while stirring. Stirring is continued until the second dye is thoroughly incorporated. The supersensitized 40 emulsion can then be coated out on a suitabie support, such as glass, cellulose derivative film, resin i-ilm, or paper; to a suitable thickness and allowed to dry. The dbtails of such coating methods are well known to those skilled in the art. 45 The amounts of the individual sensitizing dyes actuallyincorporated in the emulsion will vary somewhat from dye to dye, according to the emulsion employed and according to th e effect de50 sired. The regulation and adoption of the most economical and useful proportions will be apparent to those skilled in the art upon making the ordinary observations and tests customarily employed in the art. Accordingly, the foregoing 55 procedures and proportions are to be regarded only as illustrative. CIearly my invention is directed to any emulsion containing a combination of the aforesaid sensitizi-?lg dyes wher6by a supersensitizing effect isobtained. 60 The following examples will serve to illustrate further the manner of practicing my in,@ention. To different portions of the same batch ofphotographic gelatino-silver bromiodide emulsion were added (1) a diaryloxycarbocyanine dye se65 lected from thbse of Formula I above and (2) a COMbination of the diaryloxycarbocyanine dye and a complex merocyanine dye selected from those represented by Formula IT above. In some instances a third coating was Prepared using the 70 same emulsion formula and adding only one of the complex merocyanine dyes selected from those of Formula rr. In general, the table will show that this third coating gave only, a low speed or one too small to measure (designated 75 in the table). Diffetent emulsions were used in

some @of @the examples, although the emulsions of ,eachindividual example are obtained from the @same batch. I-lowever, the coatings of Examples I to 5 were from the sa@me batch of emulsion, the coatings of Exaniples 6 @to 9 were from the same 5 batch of emulsion, the-coatings of Exainples 10 to 18 were, from the same batch of emulsion. and the: coatings of Exarnples 19 a@nd 20 were from the:same @batch of emulsion. Before coating, the emulsions containing the sensitizing dyes were 10 digested for a short time:in a tank maintained at :52.1 C., and the sensitized emulsion coated and processed. The different portions of emulsion were then coated Qn glass supports and ex osed @p Pin the usual -manner @in a spectrograph and a 1@5 sensitomet er (type lb) through a Wratten 25 filter, i. e. a filter which transmits substantially no light of wavelength sho,rte@r than 580 mg. Following are several examples of @such emulsions to@gether with the speed (red), gamma and fo ob- 20 9 tained 6 the @sensitivity conferred on the emulsion by the complex merocyanine dye, alone is shown, since the sensitivity conferred by the complex merocyanine in question is too weak to be significant in the comparisons shown. In Fig. 1, curve A represents the sensitivity of an ordinar gelatino-silverbromiodide emulsion y sensitized with 8,10-d i(p-chlorophenoxy)-3,@'dimethyl - thiocarbocyanine p-toluenesulfonate, and curve B represents the-sensitivity ofthe same emulsion containing 8,10-di(P-chloropbenoxy)3,3'- @dimethylthiacarbocyanine P-toluenesulfonate and 5-[(Ietbyl-2(l)-p-naphthothiazolylidene) -a -ethylethylideriel-3-p-.methoxyeth @ yl2(3 -@p -methDxyethyl-4- oxo-2-thioro-5-thiazolidylidene) -4-thiazolidone; The@ sensitometric measureinents for these emul@@ions are given in @Example 5 of the above table. In Fig. 2, curve C represents the sensiti vity of an Qrdinary gelatiijo-silverbromiod !de emulsion 5eiasitized with 3,3'-dimethyl-8,10-di(ni-toloxy)- Y,Xampjp@ Dye (g. per. mole of silver halide in emulsion) S p e e d , @ G a m m a F o g (a) 5-[(l-(,.tbyl-2(l)-fl-naphthotlliazolylideiae) -a-ethylethylidenej-3-,6- methoxyethyl-2-(3-8-methoxyethyl4-oxo-2-thiono-5-thiazolidylidene)-l-thiazolidone (0.001)@ -------------------------------- ----- --- 2.55 3.0 04 (b) dye (a) (0.020) ------------------------------- --------------------------- ---------------------------- -22. 5 4.1 05 ------ (e) dye (a) (0.040) ------------------ ----- ------------------------------------------------------------ ---- 26.5 4@@5 .05 (d) dye (4) (0.080) ------------------------- ----- -------------------- ------------ -------------------I--- 16.10 3.1 .06 (,) 8 ln-di(p-methoxypbenox),)-3,31-dimethylthiacarbocyanille bromide (0.080) ------ --------------------- 21@'@5 2.22 .05 (f) d'@e (a) 0.001) witb dye (@) (.080) ----------- ---------------------------------------------- - I ---------- 30.@O 12.65 .04 2----@ ---- (q) dy(,, (q) (0@040) with dye (e) (.080) ---- ------------------------------- --------------------------------- 40.0 3. 29 @ 06 3 (li) 3,31-dimethyl-8,10-dipbcnoxytl, iacai-bocyaiiiiie bi-oinide (0.080) ----------------- ---------------------- 22.5 2@'4 (i) (lye (a) (0.001) witli a.ye (4) (O.Oso) ------------------------------------------- ------------------------ 25.5 2. 6 'O' dye (d) (0.040) V7ith dye (h) (0.060) -------------------------------------------------------- ---------- 34 0 3. 74: -05 4-1 ------- .07 -5 8,10-(Ii(p-chloi,ophe.noxy)-3,3'-dim etby)thiacai,bocyanin@. p@toluenesulfonate (0.080) ------------------- 2i. 5 2. 70 .05 dye (k) (0.030) wit-h dve (a) (o.ool) ------------------------ ----------------------------- --------------- 34. 0 4.2 .05 6 3,10-di(m-toloxy)tbiacarbocyaniTie bi-omide (0.080) ------------------------ -----------7 27. 0 3.'14 .08 h dye (,i) (O.'001) ------------------------------- ---------------------------------- 36@'O -3.20@ 09 hyl2(3)-a-naphtliothi,,izolvlidene)ethylidenel-2-ft-me thoxyethyl-2.(3-0-Methoxy. 7--------- e tliiazolidyliden e)-4-thiazofidoiie (0.001) ---------------------- ----------------- --- 2.8 .1.2 05 (p) witb dye (m) (0.080) ----------- ---------------------------- ----- 38. 0 3.10 09 8 (q) 3- (l)-quiiaolvlidene-2-(3-ethyl -,I-oxo-2-thiono-5-thiazolidylid-ei@@)- -4@-t-h-i-a-z-o-l-i-d-o-n-e--(-O.001) (r) d with dye (q) (0.001) ------------------- - - ------------------------------------ 31.5 2.98 W (s) 3-et 3-ethyl-2(3)-benzoxazolylidene)ethylidene]- - y -4-oxo-2-thiono-5- tbiazolidyIidene)-4- 9---- ---- thiazoli (0.001) ----- --------------------------------------------------- --------------------- ------- 2.2 3.2 .04 ,(t,) dye (s .001) with dve (m) (0.080) ----------- ------------------------------------------------------- 34. 0 3.22 .05 (it) 3,3'-dimethyl-8,10-di(m-toloxy)tbi@carbocyaniiie bromide (0.080) ------------ i@i@ ----- ---------------- 16.2 2. 79 08 10 (V) 2-(3-carbethoxymethyl-4-oxo-2-th iono-5-thiazolid@,lidene)-3-othyl-5-[.(Iethyl- - p - naphtbothiazolylidene)-@-pthvlothylidenel-4-thiazolidone (0.001) --- ----------------------------------------------------- - 2. 7 2.65 04 (w) dye (7i) (b.080) with dve (v) (0.001) ---------------------- - -------------------------- ----- 25.0 2.30 08 (x) 2-(3-carbotho),ymethyl-'4-oxo-2-thiono-5-thi,@i zolidylideTle)-5-if@i-l-i-f@f -ethyl2(i)-fl-naphthothiazolyli11 -------- dene)isopropylidene]-4-thiazolidone (0.001) ------------------------------------------ ------------------- 2. 2 0.88 05 (li) dye (x) (0.001) with (lye (n) (0.090) -------- ---------------------------------------------- ------------ .29.@o 2.60 :08 (z) 5-[(l-ethyl@2(l)-o-naphthothiazolylidene)@-I)h enylethylidenel-3-,6- methoxyethy1-2(3-0-methoxyethyl. 12 -------- T4-oxo-2-thiono-5-tliiazolidylidene) -4-tbiazolidone (0.001) ------------------------- ----------------------- 3. 7 3.29 04 (a') dye, ((z) (0.001) with dye (u) (O.O@.@0) ----- ------------------------------------------------------- ----- 34.0 2.41 08 (bl),,5-[(l-ethyl-2(l)-fl-na,phthothiazolyli(ione)e t,hylideiie]-3-p-metho.xyethyl-'-)(3-#- mothoxyethyl-4-oxo.2. 13 -------- thiono-5-thiazolidylidene)-4-thiazolidone (0.001,) ------------------------------------- ------------------- 3. 2 .2.@10 04 (c') dye (b') (0.001) Y@,ith dye (,u) (0.080) ----- --------------------------------------- 24.5 '2. 90 08 ) 9-(3-carbothoxymethyl-4-oxo-2-thiono-5-thiazolidy lidene)-3-ethyl.5-[(I-ethyi--i(f)--#-i-l-ap-h-t-h--a-t-h-i-a'14 -------- zolylidene)ethylidene]-4-thiazolidone (0.001) ----------------------------------- ------- ---------------- 2; 65 2.12 04 el) dye (d') (0.001.) with dye (u) (0.080) -------- ---------------------------------------------------------- 26.5 '2.71 .@04 oxymethvl-4-oxo-2-thiono-5- thiazolidylidene)-3iethyl.5[(3- ethyl@2(3)@benzothiazol7lidene) 15 -------- (0.001) - --------------------------------------------------- ------------------- 2.95 2.61 .04 dye (u) (0.080) ------- ----------- 23.@5 2.99 08 i a z o i i 1 6 - - - - - - - - d y l z o - - - - - - - - - - - - - - - - - - - - - - I - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - (i') d ith (O:Ogo) ---------------------------- ------------------------------------- 23. 0 2. 47 06 (j') 3- lylideiie)-- ethylethylideiie]-2-(3-,6-hydroxy-,8-ethoxy-fl-ethoxy17 -------- ethy - 74-thiazolidone (0.001) ------ ------------------------------- ---- 2.55 1.41 04 (k') dye (1') (0.001) wit ----------------- --------------------------- 31.5 2.91 .09 (11) 2-(3-carbethoxymet y 4-oxo-2-thioDo-,5-thiazol idiifd@@;5-3---e-th-y-l---5--[-(-3-ethyl-4-phonyl-2(3)-benzo18 -------- thiazolylidene)ethyliden@1-4-tbiazolidone (0.001) ---------------------------------- --------------------- 3.15 3.01 .04 (m') dye (1') (0.001) witli dye (7t) (0.090) ------ --------------------------------------------- ------------- 25.5 2.95 09 19 -------- (n') 3,31-(Iimethyl-8,10-di(m-toloxy)t hiaeirbooyanine broraide (0.080) ------------------------------------ 27. 0 3 4 08 (o') dye (n') (0.080) ivith dye (a) (0.001) ---- -------------------- -- - ------------------------------ 36.0 3:210 09 (PI) 5-(3-ethyl-2(3)-benzothiazolylidene)-3-ethyl-2 -(3-ethyl-4-o@i-i-ifilo-i-ao-5- thiazolidylidene)-4-thiazoli 20 -------- done (0.001) ------------------------------------------ -------------------------------------------- (q') dye (p') (0.001) with dye (,a') (0.080) ------ --------------------------------------------- -------- 301.0 2. 36 .06 thiacarbocyanine bromide, and curve.D 'represents the sensitivity of the same emulsion contaiiiing 3 ' 3'-dimethyl-8110-di (M-toloxy) thiacarbocyanine bromide and 5-[(3@p-hydroxyethyl2(3) - anaphthothiazolylidene)ethylidenel-3-9methoxyethyl-2- (3-p-methoxyethyl4-oxo-2-thi@oro@5-thiazolidylidene) -4-thiazolidone. The'sensitomet@ric @.measurements @for @.these.emWsions are given in Example 7 of the above table. In Fig. @ 3, curve E represents the sen@itivity of an ordinary gelatinosilver@bromiod ide uision : e m @The accompanying drawing illustrates the su- 05 '@tizing effect obtsined with three of my persens@ new combinations in silver bromiodide emulsions. Each figure of the drawing is a diagrammatic reproduction of two spectrograms. In each fig:ui-e the sensitivity of the emulsion containing 70 t,he diaryloxycarbocyanine dye is represented by the lonver curve. The upper curve @represents the sensitivity conferred on the @emulsion by the @com'.bination of the diaryloxycarbocyanine dye and No urve@-showing @75 ,the complex merocyanine dye@ -(@ @RedLigbtExposure

-!t,686,961 7 sensitized -with 3,@l-dimethyl-8,10-d . i( - m-t6loxy')- thiacarbocyanine bromide, and curve F represents the sensitivity of the same emulsion containing 313'-dimethyl-8,10-di(mtoloxy)thiacarbocyanine bromide and 2-(3-carbethoxy-methyl- 5 4 - oxo - 2 - thioro-5- thiazolidylidene) -3-ethyl-5[ (I - ethyl-2 (1) -,6- naphthothiazolylidene) isopropylidenel - 4 - thiazolidone. The sensitometric measurements for these emulsions are given in Example 11 of the above table. lo My invention is primarily directed to the ordinarily employed gelatino-silver-halide developing-out emulsions, e. g. gelatino-silver-chloride, -chlorobromide, -chloriodide, - chlorobromiodide, obtained using gelatino-silver-bromiodide emulsions, excellent results have also been obtained using gelatino-silver-chlorobromide emulsions. Emulsibns which form the latent image mostly in20 side the silver halide grains, such as the emulsion set forth in U - S. Patent 2,456,956, dated December 21, 1948, can also be employed in practicing my invention. The emulsions prepared in accordance with MY 25 invention can be coated in the usual manner on any suitable support, e. g. glass, cellulose nitrate film, cellulose acetate Mm, polyvinyl acetal resin film, paper or metal. The following examples will serve to illustrate 30 the manner whereby the complex merocyanine dyes used in my invention can be prepared. Exantple 21.-5 - I (i -ethyl-2 (1) -p-naphthothiazolylidene) - a -ethylethylidenel -3-p-methoxyethyl - 2-(3-p-methoxyethyl-4-oxo-2-thiono-5- 35 thiazolidylidene) -4-thiazolidone 8 '2.79 @. (1 mol.) of methyl-ptoluenesulfohat e was fused over a free flame and then heating was continued at the temperature of the steam bath for 4 hours. This crude addition product, 2.87 g. (I mol.) of 3-pmethoxy ethylrho danine and 1.60 g. (I mol. plus 5% excess) of triethylamine in 50 ml. of absolute ethyl alcohol were heated together at the reflluxing temperature for 30 minutes' After cooling, the dye was collected on the filter and washed with methyl alcohol. The crude dye was dissolved in hot pyridine and precipitated from the pyridine filtrate by the addition of methyl alcohol. After another such purification the yield of dye was 780/o. The The 3-pmethoxyethyl rhodanine used above was prepared as follows: A mixture of 50 g. (I mol.) of 8517,, p6tassium hydroxide dissolved in 300 ml. of water and 77 9. (1 mol.) of a 72% aqueous solution of pmethoxyethyl amine was stirred mechanically as 57 g. (I mol.) of carbon disulfide was added, over a period of 30 iiiinutes. The reaction mixture wAs heated, with stirring, on the steam bath for about 2 hours. After dissolving 72 g. (1 mol ' ) of chloroacetic acid in 100 ml. of water the @olution was neutralized with sodium carbonate and the resulting solution was added to the r,,action mikture. The mixture was stirred for about one hour, stood overnight at room temperature and then made acid to Congo red paper with dilute sulfuric acid. About two hours later the oily layer was collected at the separatory funnel. The aqueous layer was extracted with benzene. The combined benzene extract and the oily layer was -bromide and -bromiodide developing-out emul- 15:purplish crystals had melting point 184- 1851 C. sions. -vvhile the results in the above table were with decomposition. S OC-NCH2CH20CH3 OC-NCH2CH20CH3 C=CH-C=C Cs C2H5 S S A mixture of 2.28 g. (1 mol.) of 5-1 (I-ethyl2(i) - p -- naphthothiazolylidene) - aethylethylidenel -3-,3-methoxyethylrhodanine and 0.93 g. (I mol.) of methyl ptoluenesulfonate were fused together bver a free fl@me and then heating was 50 continued for 4 hours at the temperature of the ,steam bath. The crude addition product, thus formed, 0.96 g. (1 mol.) of 3-p-methoxyethylrhodanine and 0.53 g. (I mol. plus 5% excess) of S triethylamine in 25 ml. of dry pyridine were heated together at the refluxing temperature for 5 minutes. After cooling, the dye was collected 65 on a filter and washed with methyl alcohol. The yield of dye was 86% crude and 72% after two recrystallizations from pyridine. The green crystals had melting point 272-2731 C. with decomposition. 70 The 5 - [ (1 - ethyl - 2 (1) -p-naphthothiazolylidene) -a-ethylethylidenel - 3 - p - me oxye ylrhodanine used above was prepared as follows: A mixture of 4.50 g. (1 mol.) of 1-ethyl2-thio4nethylene - washed- with water, and then the benzene was removed byfracti.onation. The residue was distilled. The 3-p-methcxyethylrhodanine distilled at 155160' C. at 20 nim. The yield of light orange oil was 83%. Example 22.-5-[(l-ethyl-2(l)-p-napthothiazolylidene) ethylidenel - 3 - p - methoxyethyl - 2 (3 - # - methoxyethyz - 4 - oxo - 2 - thiono - 5 thiaxolidylidene) -4-thiazolidone 00-NCH2CH20CH3 OC-NCH2CH20CH3 A mixture of 2.14 g. (I mol.) of 5-1(1-ethyl2 (1) - p -- naphthothiazolylidene) ethylidene I - 3 6-methoxyethylrhodapine and 3.3 g. (I mol. plus 300% excess) of methyl-p-toluenesulfonate was heated for 4 minutes at 160, C. Tlle crude addition product, thus formed, and 1.2 g. (i mol.) of 3-p-methoxyethylrhodanine in 25 iul. of dry Pyridine were heated together to the !)oiling point, then 0.5 g. (I mol.) of triethylamine was added an e reaction mixture was heated at the refluxing temperature for 30 minutes. After chilling, the dye was collected on a filter -@-nd washed @ Yi S C=CH-CH=C C@ @C @s S S c2H5 prpplo 6 - naphthothiazoline and 75 :with meth alcohol. The yield of dye wa 75% 4y

crude and,@ 38% after two recrystalliz-ations from pyridine. The green crystals had melting point 292-2959 C. with d edomposition; The@ 5 - I (1: - ethyl@ - 2 (1) - p - naphthothiazolylidene) ethylidenel - 3 - methoxyethylrho- 5. danine used in the above example was prepared as follows. A mixture of 27.2 g. (1 mol.) of 2 - acetanilidovinyl - p - naphthothiazole etho-p-toluenesulfonate, 9.6 g. (1 mol.) of 3-p-methoxyethylrho- 10 danine and 5'.0 g. (I mol@) of triethylamine in 100 ml. of pyridine was heated at the refluxing temperature for 2 hours. ter chilling@ the solid was collected on a filter and washed w I ith methyl alcohol. The rewaining residne was stirred with 15 s 500 ml@. of hot methyl alcohol and the @uspensioA 2 5 was filtered hot. After another such treatme@nt with@ hot methyl@ alcohol@ the yield of d@le was 61,,% andi, the g-reen crystals had meltino,@ point 239241- C. with decomposition. Example 23.-5 - E (3 - p - hydroxyethyl - 2 (3) - 30 c& - naphthothiazolylidene) ethylidenel - 3- -,3 methoxyethyl - 2 - (3 - p - ?netho@.,c,@,ethyl - 4 oxo - 2@ - thiono - 5 - thzazolylidene) - @l - thiazolidone rhod.anine' arl-d 1.01 g. (I mol.) of triethylamine in 250 ml. of absolute eth 1 alcohol was heat ed y at the refluxing temperature. for 50 minutes. After chilling@ the sblids were collected on the @ilter7aa@d.washed,with@methyl.alcohol. The resi@, due was,transferred to a beaker., stirred with hot methyl alcqhol and the,@ suspen8ion was filtered hbt. The yield of reddish crystals after olae recrystallization was 25%. Example 24.-5@ - I (1 - ethyl - 2 (1) naphthothiazolVlideno-)@ - a - phenylethylidenel -@3-- A methoxyethyl . 2@ - (3 - p - methoxyethyl - 4 oxo - 2, - thiono - 5 --@tltiazoZidylidene) - 4 - thiazolidone 0 C NCH2CH20CII3 00-NcHgCII20CII3 0--CH-C=G C 0 s I C..H, \ s A rgixtiire of 1.68 g. (1 mol,) of 5-[(I-ethyl@2(l)@ naphthothiazolylidene) - (x - phenylethylidenel, - 3 - p - methox@ethylrhodanine and 1.24 g. (I m6l. plus 100% excess) of methyl ptoluonesulfonate, was fused over a free flame for afewminutes. The,Qrudeadditionproduct.thus formed, 0 @.64 g. (1 rnol.). of, 37,6-methoxyethYI7 rhodanine@and 0.36 g. (I mol..Plus 5% excess) of triethylamine in, 15 ml,,of dry pyridine were heat-, ed together at the refluxing temper-,tture for 7 00,-NCH2CH20CH3, OC-NCH2CH20CH3 C=CH-CH=@ C' Cs NI s s CH,CH,oll A mixture of 1.11 g. (I mol.) of 5-[(3-p-hydroxyethyl - 2(3) - cc - naphthothiazolylidene) ethylidenel@ -3@P-meth@oxyethylrhodanine- and@ 0;93 g. (i mol. plus 100% excess) of mf-tbyl P-tolu- 50 enesulfonate was heated together at the temperatui:e @ of the steam bath for 6 hours. The crude addition product, 0.46@g. (1 mol.) of 3-0@methoxyethylrhodanir xe, and O@25 g. (I mol.) of triethylamine@@ in 25 ml. of dry pyridine were heated to- r)5 gether at the refluxing temperature for 5 minutes,. The@ cool reaction mixture was stirred with sqme@ rnet.hyl alcohol and the whole Tjas chilled. The- zqlid was collected on a. L-ilter and washed with methyl, alcohol. The residue .vas stirred 60 @vith 300 ml. of boiling methyl alcohol and the suspension was filtered hot. After a@,iother such treatment, the dye was dissolved in boiling pyridine and preizipitated by adding, methyl alcohol to the filtered pyridine solution. The. yield Of. 65 dye,after@ another: such purification waz 33 %., The dark green crystals had melting point 299-3010 C. with decomposition. The 5 - 1(3 - p@ - hydroxyethyl - 2 (3) -@ a - naphthothiazolylidene) ethylidenel - 3 - g - methoxy- 70 ethylrhodanine used in the above example was prepared as follows@: A mixture of 4@27 g. (I m,'ol.) of 2-p-anilinovinyl, - a - naphthothiazole - e - hydroxyethobromide, 1.91 g. (1 mol.) of 3-pme',hoxyethyl- 7r) minutes, The cool reaction mixture was stirred with ether. After chilling, the dye was colleqted onafilterandwashedwithmethyla'.cohol. The@ dye was, dissolved in boiling pyridine@ and precipitated by addiiigmethyl alcohol@ to the@ filtered Pyridine@solutioni The yie ' Id of dye after anqther@ suchpurificationwas52%. The@darkgreenc.rys tals had melting point 3111 C. with decomposition. The 5 - I (I - ethyl - 2(1) - e - naphthothiazolylidene.) -a-phenylethylidqnel - 3 - g% - methoxyethylrhodanine@ used in the abo e example 'Y was prepared as @fgllows A mixture of 10-41 g. (I mol.). of I-ethyl-2@, thiobenzoyl,methylene-p-naphthothiazolinei and li-58 g. (1 mol.) ofmethyl ptoluenesulfonatq wa-s heated@ over a free flame@ The crude addition. product, 5,73 g. (I mol.) of. 3-p-methoxyethylrhodanine and 3.18@ g. (i@l mol@ plus, 5% excess) of triethylamine in 100 ml.. of absolute ethyl alqohol were: heated togpther at the refluxi:ng temperature for 40 minutes. After chilling@ th reaction., mixt@ure, was@ stirred with ether, the suspension, was filtered and@ the, residue @vas @vashed, with ether. The, crude dye was dissolved@. in hot Pyridine and precipjtatedi from@ the pyridine filtrate by the addition of ethyl alcohol., After two further purifications the yield of dye was 22%. The green crystals had melting point 242-243' C. with decomposition.