Classifications

• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03C—PHOTOSENSITIVE MATERIALS FOR PHOTOGRAPHIC PURPOSES; PHOTOGRAPHIC PROCESSES, e.g. CINE, X-RAY, COLOUR, STEREO-PHOTOGRAPHIC PROCESSES; AUXILIARY PROCESSES IN PHOTOGRAPHY
  • G03C1/00—Photosensitive materials
  • G03C1/005—Silver halide emulsions; Preparation thereof; Physical treatment thereof; Incorporation of additives therein
  • G03C1/06—Silver halide emulsions; Preparation thereof; Physical treatment thereof; Incorporation of additives therein with non-macromolecular additives
  • G03C1/08—Sensitivity-increasing substances
  • G03C1/28—Sensitivity-increasing substances together with supersensitising substances
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03C—PHOTOSENSITIVE MATERIALS FOR PHOTOGRAPHIC PURPOSES; PHOTOGRAPHIC PROCESSES, e.g. CINE, X-RAY, COLOUR, STEREO-PHOTOGRAPHIC PROCESSES; AUXILIARY PROCESSES IN PHOTOGRAPHY
  • G03C1/00—Photosensitive materials
  • G03C1/005—Silver halide emulsions; Preparation thereof; Physical treatment thereof; Incorporation of additives therein
  • G03C1/06—Silver halide emulsions; Preparation thereof; Physical treatment thereof; Incorporation of additives therein with non-macromolecular additives
  • G03C1/08—Sensitivity-increasing substances
  • G03C1/10—Organic substances
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03C—PHOTOSENSITIVE MATERIALS FOR PHOTOGRAPHIC PURPOSES; PHOTOGRAPHIC PROCESSES, e.g. CINE, X-RAY, COLOUR, STEREO-PHOTOGRAPHIC PROCESSES; AUXILIARY PROCESSES IN PHOTOGRAPHY
  • G03C1/00—Photosensitive materials
  • G03C1/005—Silver halide emulsions; Preparation thereof; Physical treatment thereof; Incorporation of additives therein
  • G03C1/06—Silver halide emulsions; Preparation thereof; Physical treatment thereof; Incorporation of additives therein with non-macromolecular additives
  • G03C1/08—Sensitivity-increasing substances
  • G03C1/10—Organic substances
  • G03C1/12—Methine and polymethine dyes

Definitions

• Light-sensitive photographic silver halide emulsions which contain (1) a photographic spectral sensitizing dye having a polarographic cathodic halfwave potential more positive than about 1.80 volts, said dye being employed in the emulsion at a concentration which results in at least about 0.3 log E desensitization of a test portion of the emulsion, when the test portion of the emulsion is coated on a support, sensitometrically exposed and developed for 6 minutes at 20 C. in Kodak D-l9 developer; and (2) an organic silver complex in an amount eifective to reduce the desensitization caused by the spectral sensitizing dye.
• Photographic emulsions in accordance with this invention exhibit higher speeds in the spectrally sensitized region (i.e., higher minus blue speeds) than prior art emulsions containing lower concentrations of spectral sensitizing dye.
• use of the higher dye concentrations in accordance with the present invention results in emulsions which exhibit sensitivity to longer wavelength radiation than prior art emulsions having lower dye concentrations.
• This invention relates to photographic emulsions and more particularly to reducing the desensitization caused by photographic spectral sensitizing dyes.
• spectral sensitizing dyes generally decrease the inherent blue sensitivity of silver halide emulsions. For each spectral sensitizer an optimum amount of dye for a particular emulsion must be determined by experimentation, and this amount is usually much less than monolayer coverage. Photographic spectral sensitizing dyes have previously been added to negative, developing-out silver halide emulsions in amounts which cause less than 0.3 log E desensitization.
• Glafkides Photographic Chemistry, volume 2, published by Fountain Press, London, 1960, states at page 922 that desensitization by dyes, such as phenosafranine, is reduced by the presence of silver ions (i.e., low pAg); and, points out at page 906 that the sensitivity of infrared plates is increased by hypersensitizing, such as by bathing in silver nitrate.
• Glafkides fails to suggest any means for elfectively using photographic spectral sensitizing dyes in concentrations which would, without some special treatment or addenda, cause more than 0.3 log E desensitization.
• One object of this invention is to reduce the amount of intrinsic blue desensitization caused when high concentrations of photographic spectral sensitizing dyes are added to photographic silver halide emulsions.
• Another object of this invention is to provide a method of increasing the efiiciency of the spectral sensitization of photographic silver halide emulsions.
• a further object of this invention is to provide a method of using high levels of photographic spectral sensitizing dyes in photographic silver halide emulsions.
• light-sensitive photographic silver halide emulsions which contain (1) a photographic spectral sensitizing dye having a polarograpbic cathodic halfwave potential more positive than about l.80 volts, said dye being employed in the emulsion at a concentration which results in at least about 0.3 log E desensitization of a test portion of the emulsion, when the test portion of the emulsion is coated on a support, sensitometrically exposed and developed for 6 minutes at 20 C. in Kodak D-19 developer; and (2) an organic silver complex in an amount effective to reduce the desensitization caused by the spectral sensitizing dye.
• Photographic emulsions in accordance with this invention exhibit higher speeds in the spectrally sensitized re gion (i.e., higher minus blue speeds) than prior art emulsions containing lower concentrations of spectral sensitizing dye.
• use of the higher dye concentrations in accordance with the present invention results in emulsions which exhibit sensitivity to longer wavelength radiation than prior art emulsions having lower dye concentrations.
• photographic spectral sensitizing dye is used herein and in the appended claims as a word of art which denotes dyes employed as spectral sensitizers in negative, developing-out silver halide emulsions. Such dyes have a polarographic cathodic halfwave potential more positive than about -1.80 volts.
• cathodic measurements are made with a 1X10- molar solution of the dye in a solvent, for example, methanol which is 0.05 molar in lithium chloride using a dropping mercury electrode with the polarographic halfwave potential for the most positive cathodic wave being designated E
• Anodic measurements are made with 1x l0 molar aqueous solvent 'solution, for example, methanolic solutions of the dye which are 0.05 molar in sodium acetate and 0.005 molar in acetic acid using a carbon paste or pyrolytic graphite electrode, with the voltametric half peak potential for the most negative anodic response being designated E
• the reference electrode is an aqueous silver-silver chloride (saturated potassium chloride) electrode at 20 C.
• Electrochemical measurements of this type are known in the art and are described in New Instrumental Methods in Electrochemistry, by Delahay, Interscience Publishers, New York, N.Y., 1954; Polarography, by Kolthofl? and Lingane, 2nd edition, Interscience Publishers, New York, N.Y., 1952; Analytical Chemistry, 36, 2426 (1964) by Elving; and Analytical Chemistry, 30, 1576 (1958) by Adams.
• the less negative (more positive) the cathodic (reduction) potential the greater is the electron aflinity of a dye and conversely the less positive (more negative) the anodic (oxidation) potential of a dye, the greater is its electron-donating ability.
• the useful photographic spectral sensitizing dyes include the methine dyes, such as the cyanine, merocyanine, hemicyanine, oxonol and "styryl dyes.
• Typical useful methine dyes are described in Brooker U.S. Pats. 1,846,- 301, issued Feb. 23, 1932; 1,846,302, issued Feb. 23, 1932; and 1,942,854, issued Ian. 9, 1934; White U.S. Pat. 1,990,507, issued Feb. 12, 1935; Brooker and White U.S. Pats. 2,112,140, issued Mar. 22, 1938; 2,165,338, issued July 11, 1939; 2,493,747, issued Jan. 10, 1950, and 2,739,964, issued Mar.
• Preferred cyanine dyes which can be employed in high concentrations in accordance with this invention have the following general formula:
• d and n each represents a positive integer of from 1 to 2
• m represents a positive integer of from 1 to 5
• Z and Z each represents the non-metallic atoms necessary to complete a heterocyclic nucleus containing from 5 to 6 atoms in the heterocyclic ring, e.g., thiazole, 4-phenylthiazole, 4,5-diphenylthiazole, 4-(2-thienyl)thiazole, 4-methylthiazole, benzothiazole, 4-chlorobenzothiazole, 4-methylbenzothiazole, 4-methoxybenzothiazole, 4-ethoxybenzothiazole, 4-phenylbenzothiazole, 5-chlorobenzothiazole, 5-bromobenzothiazole, 5- methylbenzothiazole, 5-methoxybenzothiazole, 5-ethoxybenzothiazole, 5-
• 1,3-diethylthia-2'-cyanine chloride 1,l'-diethyl-2,2-cyanine chloride 3,3'-diethyloxacarbocyanine 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 1,3,3'-triethylbenzimidazolo-oxacarbocyanine iodide 5-chloro-1,3,3-triethylbenzimidazolo-oxacarbocyanine iodide 5,6-dichloro-1,3,3'-trieth
• L represents a methine group, such as those mentioned above;
• Z is selected from a value given for Z and Z above;
• R is an alkyl or aryl group, such as those referred to above;
• j and k each represents a positive integer of from 1 to 2;
• Q represents the non-metallic atoms necessary to complete a heterocyclic ketomethylene nucleus of the type used in merocyanine dyes typically containing hetero atoms selected from nitrogen, sulfur, selenium and oxygen, such as a 1,3-dioxane-4,6-dione nucleus, e.g., 2,2-dialkyl-1,3-dioxane-4,6-dione, etc.; a 2-pyrazolin- 5-one nucleus; e.g., 3-methyl-1-phenyl-2-pyrazolin-5-one, 1-phenyl-2-pyrazol
• 3-carboxyalkylrhodanines e.g., 3-(2-carboxyethyl)rhodam'ne, 3-(4-carboxybutyl)rhodanine, etc.
• 3-sulfoalkylrhodanines e.g., 3-(2-sulfoethyl)rhodanine, 3-(3-sulfopropyl)rhodanine, 3-(4 sulfobutyl)rhodanine, etc.
• 3-arylrhodanines e.g., 3-phenylrhodanine, etc., a 2(3H)-imidazo[1,2-a]pyridone nucleus; a 5,7-dioxo-6,7- dihydro-S-thiazolo[3,2-a]pyrimidine nucleus, e.g., 5,7-dioxo-3-phenyl-6,7-dihydro thiazol
• Q and Q each represents the atoms to complete a ring containing from 3 to 4 carbon atoms, one nitrogen atom and one atom selected from the group consisting of nitrogen, oxygen, sulfur and selenium.
• Typical useful merocyanine dyes are described, for example, in Brooker et al. US. Pats. 2,493,747 and 2,493,748, both issued Jan. 10, 1950.
• photographic spectral sensitizing dyes are employed in concentrations which would normally cause at least 0.3 log E desensitization in the emulsion in which the dye is incorporated.
• the amount of dye which will cause 0.3 log E desensitization can be determined by adding various amounts of dye to a test portion of the emulsion, coating the emulsion on a support, sensitometrically exposing the emulsion and developing for 6 minutes at 20 C. in Kodak D-19 developer.
• concentrations have previously been about 3 to 10 mg. of dye per mole of silver halide.
• Infrared sensitizers generally have E values more positive than -1.0, such as .2 to .9, and .E, values more negative than about +.6, such as +.2 to +.6. Infrared sensitizers sensitize silver halide to radiation longer than about 700 nm.
• Other photographic spectral sensitizing dyes such as certain cyanine and merocyanine dyes, have been used in concentrations of up to 200 mg. (or more) of dye per mole of silver halide without causing 0.3 log E desensitization. These dyes can be effectively used at still higher concentrations in accordance with this invention.
• This invention allows monolayer dye coverage of the silver halide grains. Dye concentrations higher than monolayer coverage appear to exhibit no advantage over monolayer concentrations.
• organic silver complexes can be used in emulsions to reduce the desensitization caused by high concentrations of photographic sensitizing dyes.
• the most useful organic silver complexes are complexes of silver with an alkyne which preferably contains from about 5 to 15 carbon atoms. Especially good results are obtained using complexes of silver with a 1-alkyne-3-ol.
• Preferred 1-alkyne-3-ol compounds which form useful silver complexes have the following formula:
• Ru CECH Rg ⁇ OH wherein R and R taken separately, each represents a phenyl group (including substituted phenyl such as chlorophenyl) or an alkyl group (which can be substituted) of from 1 to 6 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, tert.-butyl, n-amyl, tert.-amyl and nhexyl, or R and R1 taken together, represent the atoms required to complete a cycloalkyl group containing from 4 to 6 carbon atoms, such as cyclobutyl, cyclopentyl or cyclohexyl.
• An especially suitable silver alkyne complex is the silver complex of l-ethynylcyclopentanol of the formula:
• carboxyalkyl-substituted thiazolinethiones such as S-carbethoxy- 4-methyl-3-carboxymethyl-4-thiazoline-2-thione
• aromatic sulfonic acids such as p-toluenesulfonic acid.
• Suitable silver complexing agents which can be employed in the practice of the invention include:
• the actual amount added depends primarily on the specific spectral sensitizing dye or dyes being used and the pAg of the emulsion. The most useful results are obtained when the organic silver complex is added in a sufiicient concentration to lower the pAg of the emulsion from about 8.5 to about 3.0 to 7.0. Emulsions are normally prepared at a pAg of about 7.5 up to 9. (Note that pAg values given herein are determined at 40 C.)
• the organic silver complexes employed in this invention lower the pAg of the emulsion, but do not cause the intolerable fog and instability which results when the pAg of the emulsion is lowered with silver nitrate.
• the concentration of dye and the optimum pAg must be determined for each sensitizing dye.
• the concentration of sensitizing dye varies over a wide range, such as from about 0.001 g. to 3.5 g. per mole of silver in the emulsion, depending on the particular dye being used.
• the dyes can be used in concentrations which give monolayer coverage of the silver halide crystals. It is preferred that the dye be incorporated in the silver halide emulsions at a temperature ranging from 40 C. to 60 C. and that the organic silver complex be added to the emulsion prior to coating.
• a gel layer imbibed in an ethanol solution of an organic silver complex for example the silver complex of ethynylcyclopentanol
• an organic silver complex for example the silver complex of ethynylcyclopentanol
• a coating containing a higher concentration of a potential desensitizing dye for example the silver complex of ethynylcyclopentanol
• Substantial speed gains can be obtained by this method. Similar results are obtained Without harmful increases in minimum density when the gelatin layer is imbibed with a solution containing a silver salt of p-toluensulfonic acid or a silver complex of a thiazolinethione such as -carbethoxy-4-methyl-3-carboxymethyl-4-thiazoline-Z-thione.
• the process of this invention is useful in spectrally sensitizing any of the photographic silver halide emulsions, including silver bromide, silver chloride, silver bromoiodide, silver chlorobromide, silver chloroiodide or silver chlorobromoiodide.
• the photographic grains can be dispersed in any suitable binder, including such hydrophilic binders as gelatin, albumin, agar-agar, gum arabic, alginic acid, polyvinyl alcohol, polyvinyl pyrrolidone, cellulose esters, partially hydrolyzed cellulose acetate, and the like.
• the binding agents for the emulsion layer of the photographic element can also contain dispersed polymerized vinyl compounds. Such compounds are disclosed, for example, in U.S.
• Emusions sensitized as described herein can be coated on any suitable photographic support, such as glass, film base such as cellulose acetate, cellulose acetate butyrate, polyesters such as poly(ethylene terephthalate), paper, baryta coated paper, polyolefin coated paper, e.g., polyethylene or polypropylene coated paper, which may be electron bombarded to promote emulsion adhesion, to produce the novel photographic elements of the invention.
• film base such as cellulose acetate, cellulose acetate butyrate
• polyesters such as poly(ethylene terephthalate), paper, baryta coated paper, polyolefin coated paper, e.g., polyethylene or polypropylene coated paper, which may be electron bombarded to promote emulsion adhesion, to produce the novel photographic elements of the invention.
• lEmulsions sensitized in accordance with this invention can contain addenda such as chemical sensitizers, e.g., sulfur sensitizers (e.g., allyl thiocarbamate, thiourea, allylisothiocyanate, cystine, etc.) various gold compounds (e.g., potassium chloroaurate, auric trichloride, etc.) (see Baldsiefen U.S. Pat. 2,540,085, issued Feb. 6, 1951; Damschroder U.S. Pat. 2,597,856, issued May 27, 1952 and Yutzy et al. U.S. Pat.
• addenda such as chemical sensitizers, e.g., sulfur sensitizers (e.g., allyl thiocarbamate, thiourea, allylisothiocyanate, cystine, etc.)
• various gold compounds e.g., potassium chloroaurate, auric trichloride, etc.
• the silver halide emulsions of the invention can be hardened with any suitable hardener, including aldehyde hardeners such as formaldehyde, and mucochloric acid, aziridine hardeners, hardeners which are derivatives of dioxane, oxypolysaccharides such as oxy starch or oxy plant gums, and the like.
• aldehyde hardeners such as formaldehyde, and mucochloric acid
• aziridine hardeners hardeners which are derivatives of dioxane, oxypolysaccharides such as oxy starch or oxy plant gums, and the like.
• the emulsion layers can also contain additional additives, particularly those known to be beneficial in photographic emulsions, including, for example, lubricating materials, stabilizers, speed-increasing materials, absorbing dyes, plasticizers, and the like. These photographic emulsions can also contain additional spectral sensitizing dyes. Furthermore, these emulsions can contain color-forming couplers or can be developed in solutions containing couplers or other color-generating materials. Among the useful color for-mers are the monomeric and polymeric color formers, e.g., pyrazolone color formers, as well as phenolic, heterocyclic and open-chain couplers having a reactive methylene group.
• additional additives particularly those known to be beneficial in photographic emulsions, including, for example, lubricating materials, stabilizers, speed-increasing materials, absorbing dyes, plasticizers, and the like. These photographic emulsions can also contain additional spectral sensitizing dyes.
• the color-forming couplers can be incorporated into the photographic silver halide emulsion using any suitable technique, e.g., techniques of the type shown in Jelley et al. U.S. Pat. 2,322,027, issued June 15, 1943, Fierke et al. U.S. Pat. 2,801,171, issued July 30, 1957, Fisher U.S. Pats. 1,055,155 and 1,102,028, issued Mar. 4, 1913 and June 30, 1914, respectively, and Wilmanns U.S. 'Pat. 2,186,849, issued Jan. 9, 1949. They can also be developed using incorporated developers such as polyhydroxybenzenes, aminophenols, 3-pyrazolidones, and the like.
• EXAMPLE 1 A non-spectrally sensitized control coating is prepared as follows. To 243 ml. of a 5 percent aqueous gelatin solution is added 72 g. of a gelatino fine-grain silver bromide emulsion containing g. gelatin per mole of silver and weighing 1.65 kilograms per mole of silver.
• the liquid emulsion is held for 15 minutes at 40 C., adjusted to a pAg of 8.5 using a solution of dimethylform-amide containing 5 percent by weight of silver ethynylcyclopentanol, adjusted to a pH of 6.5, combined with a surfactant and a hardener and coated on a gelatin subbed polyethylene terephthalate support at 0.004 inch.
• the dried coatings are exposed in a wedge spectrograph for A second at 1.0 mm. slit width and developed in Kodak D-19 developer at 20 C. for 2 minutes.
• the element is assigned a relative blue speed at 400 nm. of and has a minimum density of 0.04.
• EXAMPLE 2 A spectrally sensitized control coating is prepared as follows. The procedure set out in Example 1 is followed with the exception that 1.5 ml. of a methanol solution containing 0.1% by weight of 3,3'-diethyl-9,11,15,17- dineopentylene thiapentacarbocyanine iodide (I) is added to the emulsion at a level of mg. dye per mole of silver. The pAg is then adjusted in the same manner as described in Example 1. The exposed and processed element has a blue speed relative to Example 1 of 0.78 at 400 nm. (which amounts to a 2.10 log E speed loss) and no spectral sensitivity at 1,000 nm. with a minimum density of 0.04.
• I 3,3'-diethyl-9,11,15,17- dineopentylene thiapentacarbocyanine iodide
• EXAMPLES 37 Five elements are prepared as described in the procedure set out in Examples 1-2 with the exception that a prescribed amount of the dimethylformamide solution of the silver ethynylcyclopentanol complex is added to the liquid emulsion melt to lower the pAg of the final melt.
• Table I lists the example number, the pAg of the melt and the relative blue speed at 400 nm. and the infrared speed at 1,000 nm. Processing is the same as in Example 1.
• Relative speed at- N oTE.Dye I 3, 3-diethyl-9, 11, 15, l7-dineopentylene thlapentacarbocyanine iodide. (The optimum concentration of this dye has previously been from about 1 to mg. per mole of silver halide in emulsions having a pAg of about 8.5.)
• Dye III causes a 0.90 log E desensitiza tion in the intrinsic blue sensitivity (400 nm.) of the silver bromide emulsion (Example 15 versus Example 16),
• Example Dye (mg/m. Ag) pAg speed blue speed speed range (nm).
• addition of an organic silver complex effectively reduces the desensitization caused by the higher dye concentration.
• Use of higher dye concentrations results in higher clear speeds and higher speeds in the region of spectral sensitivity (minus blue speeds) than emulsion containing optimum dye concentrations but no organic silver complex.
• spectral sensitivity minus blue speeds
• other photographic spectral sensitizing dyes including all of those referred to above.
• organic silver complexes such as silver and ptoluenesulfonic acid complexes or complexes of silver with 5-carbethoxy-4-methyl-3-carboxymethyl-4-thiazoline- 2-thione.
• a light-sensitive photographic silver halide emulsion containing (a) a photographic spectral sensitizing methine dye having a polarographic cathodic halfwave potential more positive than about -1.80 volts, said dye being employed in said emulsion at a concentration which results in at least about 0.3 log E desensitization of a test portion of said emulsion, when said test portion of said emulsion is coated on a support and sensitometrically exposed and developed for 6 minutes at 20 C. in Kodak D-19 developer; and,
• Rn CECH wherein R and R taken separately, each represents phenyl or an alkyl group containing from 1 to 6 carbon atoms and, taken together, R and R represents the atoms required to complete a cycloalkyl group containing from 4 to 6 carbon atoms.
• a light-sensitive photographic silver halide emulsion containing (a) a photographic spectral sensitizing cyanine or merocya-nine dye having apolarographic cathodic halfwave potential more positive than about 1.80 volts, said dye being employed in said emulsion at a concentration which results in at least about 0.3 log E desensitization of a test portion of said emulsion, when said test portion of said emulsion is coated on a support and sensitometrically exposed and developed for 6 minutes at 20 C. in Kodak D-19 developer; and,
• Rn CECE wherein R and R12, taken separately, each represents phenyl or an alkyl group containing from 1 to 6 carbon atoms and, taken together, R and R represent the atoms required to complete a cycloalkyl group containing from 4 to 6 carbon atoms.
• a light-sensitive photographic silver halide emul sion containing (a) a photographic spectral sensitizing dye having a polarographic cathodic halfwave potential more positive than about l.80 volts, said dye being employed in said emulsion at a concentration which results in at least about 0.3 log E desensitization of a test portion of said emulsion, when said test portion of said emulsion is coated on a support and sensitometrically exposed and developed for 6 minutes at 20 C. in Kodak D-19 developer, said dye having one of the following formulas:
• Z, Z and Z each represents the non-metallic atoms required to complete a heterocyclic nucleus containing from 5 to 6 atoms in the heterocyclic ring; each L represents a methine linkage; R R and R each represents an alkyl group, an alkylene group joined to a methine linkage, or an aryl group; Q represents the non-metallic atoms required to complete a heterocyclic ketomethylene nucleus containing from 5 to 6 atoms in the heterocyclic ring; m represents an integer of from 1 to 6; d, n and j each represents an integer of from 1 to 2; k represents an integer of from 1 to 3; and, X represents an acid anion; and,
• said dye is an infrared sensitizing dye which has a cathodic polarographic halfwave potential between about .2 and .9 volts and an anodic polarographic halfwave potential between about -
• a light-sensitive photographic silver halide emulsion containing about 400 mg. per mole of silver of 3,3'-diethylthiacarbocyanine chloride, said emulsion containing a sufiicient amount of silver ethynylcyclopentanol complex to lower the pAg of the emulsion from 8.5 to about 5.0 to 6.0.
• a light-sensitive photographic silver halide emulsion containing (a) 3,3 diethyl-9,l1,15-17-dineopentylene thiapentacarbocyanine salt, said dye being employed at a concentration which results in at least about 0.3 log E desensitization of a test portion of said emulsion, when said test portion of said emulsion is coated on a support and sensitometrically exposed and developed for 6 minutes at 20 C. in Kodak D-19 developer; and,
• a light-sensitive photographic silver halide emulsion containing (a) 1,3-diethyl--[4-(3-ethyl-2-henzothiazolinylidene)- Z-butenylidene]-2-thiobarbituric acid, said dye being employed at a concentration which results in at least about 0.3 log E desensitization of a test portion of said emulsion, when said test portion of said emulsion is coated on a support and sensitometrically exposed and developed for 6 minutes at 20 C. in Kodak D-19 developer; and,
• a light-sensitive photographic silver halide emulsion containing (a) 3,3-diethylthiacarbocyanine salt, said dye being employed at a concentration which results in at least about 0.3 log E desensitization of a test portion of said emulsion, when said test portion of said emul- 14 sion is coated on a support and sensitometrically exposed and developed for 6 minutes at 20 C. in Kodak D-19 developer; and,
• a light-sensitive photographic silver halide emulsion containing (a) 5,5 dichloro-3,3',9-triethylthiacarbocyanine salt, said dye being employed at a concentration which results in at least about 0.3 log E desensitization of a test portion of said emulsion, when said test portion of said emulsion is coated on a support and sensitometrically exposed and developed for 6 minutes at 20 C. in Kodak D-19 developer; and
• a light-sensitive photographic silver halide emulsion containing (a) anhydro-S,5',6,6-tetrachloro 1,l,3 triethyl-3'- (3-sulfobutyl)benzimidazolocarbocyanine hydroxide, said dye being employed at a concentration which results in at least about 0.3 log E desensitization of a test portion of said emulsion, when said test portion of said emulsion is coated on a support and sensitometrically exposed and developed for 6 minutes at 20 C. Kodak D-19 developer; and

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• 1970
  • 1970-12-04 US US95420A patent/US3706569A/en not_active Expired - Lifetime
• 1971
  • 1971-11-04 CA CA126,844A patent/CA962880A/en not_active Expired
  • 1971-12-01 DE DE19712159631 patent/DE2159631A1/de active Pending
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