Патент USA US2132866код для вставки
Oct. 11, 1938. a H, CAR'ROLL l PH'OTOGRAPHIC EMULSION . v2,132,866 ` 'Filed Maron 29, 1937 A Emmen-mu; ' INVENFOR: „OMJ ATT RNEY . Íncred_°o~.11»_oßß “ 1 ' Y ~ _2,132,866A UNITED STATES AP_ATE1S1T` oi-‘Ficlaz¥ PHOTOGRAPHE) EMULSION Burt H. Carroll, Rochester, N. Y., assigner to East man Kodak Company, Rochester, N. Y., a _cor poration of New Jersey ’ y ‘ y Application March 29, 1931,' serial No. 133,583 12 Claims. (Cl.` 95-7) l This invention relates to .sensitizedfphoto- for which the other dye does not sensitize; vfor graphic emulsions- >and more particularly to photographic emulsions, such as4 those of the example, when the red sensitization produced by dye A increases in the presence of dye B which gelatino-silver-halide type, containing a mixture 5 or combination of two ormore sensitizmgma' terials, at, least one of whichcooperates with'at least one other to alter the sensitivity of ' the Aemulsion to a greater degreethan is possible With any one of the sensitizing materials alone. 10 The sensitization produced by my combination is always -greater, in some spectral region, than the sum total of the sensitizations produced by the separate sensitizing materials. The sensitizîng materialsv of my combinations are substances 15 generally referred to as dyes and more partic-k .ularly as dyes of the cyanine class. . A ' sensitizes only for the green. When two or more dyes sensitize for approximately Athe same or- 5 kWidely overlapping spectral regions (as in anum- A ber of the eases to be described in the instant application), supersensitizotion oon Still bode tested, because if supersensitization obtains in Such cases the total optical sensitization pro- 10 duced by a Combination of two'- or more dyes Will always'fbe greater, under favorable Conditions. than that which can be produced 'by any dye of the combination alone at any _Conoentration- ' The magnitude of the supersensitization depends 15 upon the relative and absolute concentrations of It is known in the art of making photograhic 'the dyes in the emulsion and 0n the type of emulsionsvthat certain dyes of the cyanine class y Y emulsion. By suitable choice of conditions su alter the sensitivity of photographic emulsions of_ `persensitization can always be made Ato assume 20 the gelatino-silver-halide type, when _incorpo- Values Which are readily observablerated therein. The sensitizing effect produced ~ M_y application deals with emulsions contain bythe dye does not increase vproportionally to Ithe amount of dye, but passes through a, maxIimum as the concentration is increased. Within . 25 the range of concentrations most usefulr in prac-_ tice, the sensitivity increases vmuch lmore slowly than _the concentration of the dye. Likewise, the 20 ing supersensitizingmixtures or Combinations of onevor more sensitlzing dyes of the 8-alkyloxa cal‘lî’ooyalîliue salts# wherein, the 8-a1kyl group cOntains at least tWo Carbon atoms With one or 25 more sensitizing dyes of the pseudoeyanine group. Just v110W the dyes of my mixtures oo combined eiïect'of'two or more dyes on an emul- ` operate to give a supersensitizing eiîect is not sionv is rarely equivalent to'the sum of'their ' 30' separate emects; in general' >it is much 1ess. known- I shall'refer to the mixtures as oom binations, although I do not intend to `imply ao Mostcommonly, the combined eñect vis no greater ‘ that the dyes are Chemically Combined than 'the eiTect of a single one of the dyes emAn object of my invention, therefore. _is to ployed- in aV concentration equal »to the»Á `sum of. provide photographie' 1 emulsi0ns~fContainin8 a` the concentrations ’or al1 the dyes »in the com-35 bination. ~Very frequently, the combined effect -of two dyes is less than that of one of them alone. . ' ' y ; ‘ ' _ . . ,Y supersensitizins combination of cyanine dyes. A further object is to provide a process for Seus- 35 itiZinE photographie emulsions With supersens itizing combinationsof cyanine dyes and to pro ' I have' found with certain combinations of two Vide a method of increasing the sensitivity of K or more cyanine dyes, that thecombined sensi- photographie emulsions sensitized With cyanine 40 tizationï-is substantially- greater, in some spectral . dyes. A stili further object is to provide a photo- 40 » region, than .that of anyone of the dyes in the vgraphic element - comprising _a Support coated' absence of the- A_other or others. I will call this with such, Super-sensitized emulsions. phenomenon supersensitiz'ation. In general, at more speoiñoobleotswilkbeeome apparent here least'l one dye of my combination may be said to inafter- » ' Other = 45 be supersensitiged -by the' other ‘or others. „ The The dyes which I employ in my supersensitiz- 45 -- dye which- is supersensitized mayv be called the ing-'combinations are lsensitizers of photographic basic sensitizer and the other dye the“ super- emulsions when used alone. While there is more sensitizer. However, the eiïect may be mutualV than one manner of formulating and naming andthe dyes indistinguishable from the stand‘ 50 point of which is supersensitized. Supersensitization is a highly speciñc phe-v nomenon and is found only in mixtures or com- „ binations of dyes from certain speciiic groups. Supersensitization can be most readily observed, _55 when adye is supersensitized in aspectr'al region the dyes which I employ in practicing my inven tion, it is believed that the formulas, systems of 50' numbering and names _used herein are in accord ance with those used during the development of _ the cyanine dye art to its present stage. ’I'he most probable formulas 'of representative dye types are given below in order to clearly set 55 aisasee 2 . . the nature?of the materials employed in my supersensitiziîig mixtures. These formulas l The benzothia-2’-cyanine dyesfwhich can beA represented by the follewing general formula: should not be construed as limiting my inven tion except as indicatedin the appended claims. Among the' B-alkyloxac'arbocyanines, useful in practicing my inìention are the following:V Y, The S-alkyloxacarbocyanines îrwhich can be represented bythe following general formula: 10 ' The oxazolo-2'-cyanine dyes,vî which can be rep resented by the following general formula: l. 15 x. 'Y In the above?. formular, A represents an'alkyl" 15 group of at least two carbon atoms, R and R’ represent alkyl groups and X represents an acid radical.; I have found it convenient- to employ Y.the carbocyanine dye-,iodides r(where X .repre 2oî sents iodine) in§practicing Amy invention.; VHow Èever, other dye=salts, such as the chlorides, bro mides, perchlorates, alkylsulfates or alkyl-p-tolu enesulfonates canbe employed,V for example. I haveA also found it advantageous to employ dyes 25 wherein A represents an alkyl groupv of from two Yto four carbon atoms, such 4as ethyl,vr isobutyl, ßl--hydroxyethyiï or allyl groups,'for example, in practicing myf? invention. More speciñcally, I havefound dyes wherein Arrepresents ethyl ari-d ‘n R and R’ represent methyl to be especially use ` ful.A The nuclei of the dyes can carry sii-nple sub i In all of the above formulas of pseudocyaniìie dyes, R and R' represent alkyl groups and» X rep resents an acid radical. 'I'he oxazolo-2’-cyanines can be substituted in the â-position- with substit uents, such as alkyl or aryl groups ofthe benzene 25 series, for example, phenyl. In practicing myän Vention, I have found it convenient tc> employ the pseudocyanine dye-iodides (wherein X repre sents iodine). However, other pseudocyanine salts can be` employed, suchf-for example as the 30 chlorides, bromides, perchlorates, alkylsulfates or stituents which do not interfere with sensitizing alkyl-p-toluenesulfonates. Ijhave further found properties, suchyas, for example, alkyl, chloro,v it advantageous :.to‘eniployfy pseudocyanine dyes alkoxy or amino groups. symmetrical and vun wherein R îand R’ represent an alkyl» group of 35 symmetrical oxacarbocyanine Ídyes can be em-` , from one toïour carbon atoms. The dyes where ployed in practicing my invention. ' in R and R' represent ethyl are particularly use The ß-alkyl'oxacarböcyanines can be'prepared' fulîn practicing myïinvention. The pseudocya by reacting 1-methy1benzoxazole quaternary salts nine dyes can be substituted in their nuclei 'with with trialkylortho esters of monobasic carboxylic y simple substituents which do not interfere with acids ofv three'?or. more carbon atoms, in the pres sensitizing properties, suchëfor example as alkyl, 40 ence of an organic base, e. g. dry pyridine, as de- ' chloro,falkoxy, or amino groups. ' scribed in UëS. Patent No. 1,962,12‘lf.4 By em ployingy mixtures ofsubstituted benzoxazole and unsubstituted benzoxa-¿zole quaternary salts, mix 45 tures of symmetricaland unsymmetrical 8-a1kyl oxacarbocyanine dyes can be obtained. Among theîpseudocyanine dyes which canè'be empigoyed in practicing my invention are the fol lowing: l:50 ï ' Y L 'The 2„2'-cya'm1neV dyes, which can be: represent-î ed by the following general formulaî » , Brooker and Keyes, in the Journal of the Amer ican Society, vol. 5T, pages 2488-2491 (1935) have reviewed 4the literature pertaining to pseudocya ninej dyes and describe methods for'the prepara tion thereof. Oxazolopseudocyanine dyes are deu scribed in U. S. Patent No.;1,969,4fi6.á 1 f The objects 'of my invention can be accom plished by merely incorporating one-or more sen sitizingI , 8-alkyloxacarbocyanine dyes together 50 with one or more sensitizing pseudocyanine dyes capable of superseïnsitizing the B-alkyloxfcarbo cyanine in a photographic emulsion. My inven / tion is particularly directed to the ordinarily em 55 pioyed gelatina-‘silver-halide emulsions. However, . iRV " ' -/ R' \x The thia-2-'-cyanine dyes, which can be repre 60 sented by'the following general formula: my supersensitizing combinations can Vbe ern-` `ployed in emulsions in which the carrier is other than gelatin, for example, a resinous substance or cellulosic derivative which has substantially no l deleterious eiïect on the light-sensitivematerials. 60 As silver halide emulsions, I >include such emul sions as are commonlyV employed inthe art, for example, ysilver chloride or silver bromide emul sions which can contain other salts which may be light-sensitive. By way of illustration,'-theherein 65 described.v supersensitized emulsions were prepared» employing an ordinary gelatina-silver-bro- - mide- emulsionyof ordinary concentration` (ap proximately 40g. of silver halide -per liter). ’I'he dyes were generallyv employed iny concentrations of the'order of liîi mg. per liter of ordinary emul sion, but can be employed in concentrations sev eral times greaterl or less than that. 'I'he ratio of concentration of the 8-alkyl'oxacarbccyanine dye to the concentration of the pseudocyanine dye 75 i aisaseo may be varied widely from 5:1 to 1:5, for exam ple. The most favorable. conditions for supersen Y ‘ . 3 . carbocyanines with pseudocyanines likewise show ` supers'ensitizing effects; " Theiï 2,2’-‘dimethyl-8- Y sitization of the desired magnitude must be de- - ethyloxacarbocyanines 'are' of particular utility termined by-experiment, the mannerof which will ' in »practicing my invention. Pseudocyanine dyes >*be apparent to A'those skilled in the art »upona com plete perusal of these specifications.` - The methods of incorporating dyes in- emul containing the 5,6-benzothia- nucleus are usually of lesser utility in- practicing'my invention.' 'I'he ' oxazolopseudocyanine dyes substituted in the 4 sions are simple'an'dwell known to those skilled ' position of the oxazole nucleus by analkyl group, ‘ vin the 'arti- In practicing my invention, the dyes i such as methyl, "or by an aryl group, such as 10 of 'my combinations can be added separately-or together. It is convenient to add the` dyes sepa - ‘rately 'in' the Vform of theirsolutions in appro - priate solvents. @The solvent must, of course, be 15P phenyl, for example,vare- especially useful in prac-- 10 ~`ticing my invention. ' ' ' Among others, the following combinations have been found'fto be `imrticularly useful: I Pteudocyaninu 15 ' za'aimeoiyieethyiomearbócya?ine iodide with l indiaan-affini“ iòdiae. 20 compatible with the emulsion,.substantially- free from any deleterious‘effect on‘the lightesensitive materials and capable of dissolving theA dyes. 25 Methanol has proven satisfactory asa solvent for In general, it can be said ofemy combinations . that‘the oxacarbocyanine‘ is ythe d_ye‘supersensi _tired (basic supersensitizer) and that the pseudo cyanine is the supersensitizer.. However, the 25 .the dyes in practicing ‘my invention. The dyes f nature of this relationship between the dyes of my -are advantageously incorporated in the ñnished, combinations is frequently dimcult to determinel washed emulsion and should be uniformly dis and is, in fact, immaterial to the practice of my, tributed throughout the emulsion. The emulsion invention. 30 can .then4 be converted into a photographic ele« . ' . Still further examples showing the application 30 of my invention could be cited, but the foregoing ment by coatingupon a support, such as glass, cellulose acetate, cellulose nitrate or other cellu will be suiiicient to teach those skilled in the art lose derivative or resin in a-manner well known in - the manner in which my invention is carried out the 35 art. f ~ i . The accompanying drawing is by Way of illus tration and'. depicts the supersensitizing effect of my new combinations. The figure of the drawing is a diagrammatic reproduction of three spectro-á and the principles of sensitizing photographic emulsions .with supersensitizing combinations, such as described herein. While I have illustrated only combinations containing- two dyes, my com binations can as well contain one oxacarbocya grams showing, first, the sensitivity of 'a silver , nine cooperating' with two or more pseudocya 40 bromide emulsion containing an _8-alky1oxacarbo nine dyes. Likewise my combinations can con Cyanine dye (represented by'the‘dot-and-dash line), second, the sensitivity'of the same silver bromide emulsion containing a pseudocyanine dye tain one pseudocyanine dye cooperating withvtwo or more oxacarbocyanine dyes. Cyanine dyes containing hydroxyalkyl groups (represented by the dotted line) ,' and third, the _ can be ~prepared from cyclammonium quaternary 45 sensitivity of the same emulsion containing a mixture or combination of the said 8-alkyloxacar bocyanine dye r`with the said pseudocyanine dye (represented by the solid line). The supersen-. sitizing effect is apparent from the drawing. f ‘ '50 More speciñcally in the drawing, curve A repre sents the sensitivity of an ordinary gelatino silver-bromide emulsion containing 2,2'-di- methyl-ß-ethyloxacarbocyanine iodide in a con , -centration of 10 mg. per liter of emulsion; curve 55 B represents the sensitivity of the same emulsion containing 3,1'- diethyl-«i-phenyloxazolo-2’- cya salts prepared by reacting heterocyclic nitrogen 45 bases with halohydrins, e. g. ethylene halohydrins - and propylene halohydri'ns. _ It is advantageous to employ the bromohydrins. The heterocyclic nitrogen base and the bromohydrin are merely heated together for several hours, e. g. 25 to 30 hours or longer, at about 100° C., though 150° C. ' can be employed. 'An excess of the bromohydrin is vadvantageously employed. Following the reac- - tion, the solid reaction product is advantageously converted to the iodide by treatment with p'otas- - 55 sium iodide. This can be accomplished by dis nine iodide in a concentration of 10 mg. per liter solving the crude Quaternary bromide in hot of emulsion, and curve C represents the same- water and treating the solution with a hot aque emulsion containing 2,2’-dimethyl-B-ethyloxacar-` ous solution of potassium iodide (1 g. per cc. of l co bocyanine iodide and 3,1’-diethyl-4`-phenyloxa-- water). Cyanine dyes containing hydroxyalkyl zolo-2'-cyanine iodide in concentrations of 10 groups are describedvin the> application of Leslie mg. and 15 mg. per liter, respectively. The sensi .G. S.Í Brooker and Lloyd A. Smith, Serial No. tivity of the emulsion represented by curve C, as 133,524, filed of even date herewith. I measured through a Minus Blue Wratten No. 12 What I claim and desire to be secured by Let 65 Filter, is about 40% greater than that of the ters Patent of the United States is: . ` ~ emulsion represented by curve A. . 1. A photographic silver halide emulsion con The spectrograms corresponding to the figures taining a supersensitizing combination of at least of the accompanying drawing were made in a one sensitizing dye, selected from the group con vni wedge spectrograph. ' The intensity of each hori sisting of ß-alkyloxacarbocyanine dyes in which' zontal line was approximately one-tenth that `at the next lower line. Where the spectrograms were compared as in the drawing, the exposures were for ‘the same time and the test plates of each dye the 8-alky1 group contains at least two carbon 70 atoms, with at least one sensitizing pseudocyanine dye. ' >were developed together. ' - , The other of my combinations of 8-alkyloxa >2. A photographic gelatina-silver-halide emul sion containing a supersensitizing combination of at least one sensitizing dye selected from the 75 45".. „. 1 ' -aisance 8. A photographic gelatino-sllver-halide emul group- consisting -of 8-alkyloxacarbocyaníne dyes in which the 8-alkyl group contains at least two sion containing a supersensitizìng combination carbon atoms, with at least one sensitizi'ng of at- least one 2,2’-dimethyl-8-ethyloxacarbopseudocyanine dye. ' cyanine dye with at least one oxazolo-2’-cyanine ‘ 3.. A photographic gelatino-silver-halide emul sion containing a supersensitizing combination vof dye. at least one sensitizing dye selected from‘the sion containing a supersensitizing combination of at least one 2,2'-dimethyl-ß-ethyloxacarbo _ group consisting of 8-alkyloxacarbocyanine dyes , " 9. A photographic gelatina-silver-halide emul in which the 8-alkyl group contains at least two 10 carbon atoms, with at least one sensitizing thia 2’-cyanine dye. -' 10. A photographic gelatino-silver-halide emul > sion containing a supersensitizing combination 4. A photographic Ígelatina-silver-halide em -sion containing- a supersensitizing combination ` of at least one 2,2’»dimethyl-8-'ethyloxacar of at least one sensitizing dye selected from the 15 group consisting lof 8--alkyloxacarbocyanine dyes s in which the 8-alkyl group contains atleast two ` s carbon atoms, with at least one sensitizing 2,2’ cyanine dye. I ` - bocyaninehalide with at least one 1,1.’-diethyl ` 2,2'-cyanine halide. , ' l5 11. A photographic gelatine-silver halide emul sion containing a supersensitizing combination of atleast one 2,2'-dimethyl-ß-ethyloxacarbo " 5. A photographic gelatino-silver-halide emul 20 sion containing a supersensitizing combination of , 12. A photographic gelatino-silver-halide emul group consisting- of 8-alkyloxacarbocyanine dyes sion containing a supersensitizing combination of at least one _.sensitizing dye selected from "the .group consisting of 8-a1kyloxacarbocyanine in which‘the 8-alkyl group contains at least two `carbon atoms, with at least one sensitizing 25 30 phenyloxazolo-2'v-cyanine halide. at least one sensitizing dye -selected from the oxazolo-2’-cyanine dye.~ _ l ' dyes in which the 8-alkyl group containsy at least 25 ‘6. A photographic gelatino-silver-halide emul two carbon atoms, with at least one sensitizing sion containing a supersensitizing combination of at least one 2,2’-dimethylf8-ethyloxacarbo-cyanine dye with at least one thial2’~cyani.ne dye selected'from the group consisting of 2,2' dye. v ` ~ cyanine dyes, thia-2’-cya,nine dyes, Selena-2ï ‘cyanine dyes, 3,4-b'enzothia-2f-cyanine dyes _and , 7. A photographic gelatine-silver-halide' emul l vsion containing a supersensitizing combination of at least one 2,2’-dimethyl-8-ethyloxacarbo cyanine' dye with at least one 2,2’-cyanine »-dye._ 12o BURT H. CARROLL.