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
  • G03C1/09—Noble metals or mercury; Salts or compounds thereof; Sulfur, selenium or tellurium, or compounds thereof, e.g. for chemical sensitising

Definitions

• This invention relates to stabilization of photographic emulsions which are sensitized with gold compounds.
• an object of my invention to provide photographic emulsions sensitized with gold compounds, which emulsions have improved resistance to loss of speed, i. e. sensitivity, on keeping or storage.
• a further object is to provide a process for preparing such improved emulsions.
• the usual procedure for preparing photographic silver halide developing-out emulsions, especially photographic gelatino-silver-halide developing-out emulsions, comprises the following stepsz (l) Precipitation-Wheiein the silver halide is precipitated by the interaction of a watersoluble silver salt and 'a water-soluble halide, in the presence of a carrier, e. g. gelatin.
• the emulsion increases in sensitivity.
• various substances have been added at various stages in the preparation of the emulsions.
• sulfur compounds i. e. so-callecl sulfur sensitizers have been added, e. g. allyl isothiocyanate, sthioure'a, thio'carbanilide, etc., have been added.
• Typical of the water-soluble gold compounds are:
• the water soluble gold compounds can be added to the emulsions in the form of solutions in suitable solvents, e. g. water, methyl alcohol, ethyl alcohol, acetone, etc., or as dispersions in colloids, such as gelatin, polyvinyl alcohol, partially hydrolyzed cellulose acetate, casein, etc., or without any solvent or colloid.
• suitable solvents e. g. water, methyl alcohol, ethyl alcohol, acetone, etc.
• dispersions in colloids such as gelatin, polyvinyl alcohol, partially hydrolyzed cellulose acetate, casein, etc., or without any solvent or colloid.
• the water soluble gold compounds should, of course, be thoroughly dispersed throughout the emulsions, e. g. by stirring.
• a concentration of the water-soluble gold compound equivalent to from 1.5 to 20 mg. of metallic gold per 1000 g. of silver nitrate used in preparing the emulsion is advantageous to employ.
• concentrations can be employed, e. g. a concentration equivalent to 1000 mg. of metallic gold per 1000 g. of silver nitrate used in preparing the emulsion.
• the water-soluble gold compounds are advantageously added to the emulsions after the final digestion, but prior to coating the emulsions on a support, at a pH of from 5 to 9, and most advantageously at pH of from 6 to 7.
• potassium chloroaurate in a concentration equivalent to 6.5 mg. of metallic gold per 1000 g. of silver nitrate employed in preparing the emulsion
• thiosinamine in a concentration of 50 mg. per 1000 g. of silver nitrate employed in preparing the emulsion
• sodium thiocyanate in a concentration of 1 g. per 1000 g. of silver nitrate employed in preparing the emulsion
• EXAMPLE 2 A batch of gelatino-silverbromoiodide emulsion was prepared as described by Trivelli and Smith--Phot.. J. 79, 330 (1939), using a precipitation time of about 20 minutes (emulsion No. 11, page 330), except that just before the final digestion of the emulsion potassium chloroaurate, thiosinamine and sodium thiocyanate were added to the emulsion in the concentrations shown in Example 1. A portion of the emulsion was coated on cellulose acetate film and dried. The film was cut into two portions and the one portion exposed and developed in the routine manner shown in Example 1 while the other portion was incubated and then exposed and $502806" 5 a.
• Trich-lorogo'ld dimethylsulfide is described by Ray and Sen-0. IndianChem. see. 7, '72-'61930); Pyridino-tri'chlorogold is described by Gmelin-Kraut llandbuch der' Anorg. Chem; V2; p. 292-3411;. Pyridinotrichloro gold andstill other of the water-soluble gold"compounds" can be" prepared as" shown the fol lowing examples.
• Alkali metal chloroaurates' e. g. potassium and sodium chloroaurates
• auric trichloride and alkali metal aurithiocyanatesand alkaliv metal aurothiocyanates are well known substances.
• Myochrysine is a. product of Merck &. Company and Solganal-B oleosum is a product. of Scheri'ng Corporation.
• My invention can be practiced onphotographi'c silver halide emulsions which have been. sensi tizedby digesting the emulsions in. the presence of either water-soluble or' water-insoluble; goldcompounds. Asshown above the sens'i'tizatiori of emulsions by digesting with water-soluble. gem compounds is well known.
• Toso sensitize amen sions at leastone water soluble goidcompofund, e. g. any or: the water-soluble gold compounds set forth above, is added tothe emulsion prior'to or during the final digestion.
• the concentration of the gold compound is equivz'a-len't to from 2.5 to 1000 mg. of gold per 1000 g. of silver nitrate used in preparing the emulsion. Most advantageously a concentration of water-soluble gold compound equivalent to from 2 tomg. of gold per kilogram of silvernitrate used in' preparing the emulsion is employed.
• the level of pH during thedigestion of the emulsion, in the presence of the water soluble gold compound is maintained 'ator below 9. although this is not essential.
• the best results are obtained by digesting the emulsions at a pH of from 5 to 9, the presence of the water-soluble gold compound.
• Digestion-of the emulsions in thepresence of the gold compounds is advantageously efiected at from-'C. tot-5 0., although other temperatures can be used. A temperature range of to C.
• the emulsions sensitized by di-- gesting with the water-soluble gold compounds are digested the additional presence of at least one sulfur compound e. g. a sulfur sensitizer; for
• Beneficial efiects are also obtained by digesting the emulsions which are sensitized by digestion in the presence of a water-soluble gold compound, in the additional presence of at least one metal or ammonium thiocyanate, e. g. alkali metal thiocyanates (e. g. sodium or potassium thiocyanate), alkaline earth metal thiocyanates (e. g. calcium, strontium thiocyanate, etc.) cadmium thiocyanate, ammonium thiocyanate, etc.
• alkali metal thiocyanates e. g. sodium or potassium thiocyanate
• alkaline earth metal thiocyanates e. g. calcium, strontium thiocyanate, etc.
• thiocyanates containing cations which cations are known to have, in themselves, a deleterious effect on silver halide emulsions should be avoided.
• iron thiocyanate which contains the iron cation should be avoided.
• One or more sulfur sensitizers or one or more thiocyanates selected from the group consisting of metal or ammonium thiocyanates can be employed.
• One or more sulfur sensitizers can be employed in conjunction with one or more thiocyanates containing a cation selected from the group consisting of metal and ammonium cations.
• the sulfur sensitizers and thiocyanates are advantageously incorporated in the emulsions in the form of their solutions in a suitable solvent, such as water, methyl or ethyl alcohol.
• the sulfur sensitizers can be incorporated in the emulsions at any stage of the preparation of the emulsions, e. g. during precipitation of the silver halides, during the first digestions (ripening) or during the second digestion of the emulsions.
• the amount can vary Widely.
• an amount of thiocyanate equal to from about to about 75 g. per kilogram of silver nitrate used in preparing the emulsion is employed. If the thiocyanate or sulfur sensitizer is not added until later in the preparation, e. g.
• the thiocyanates an amount equal to from about 0.1 to about 10 g. per kilogram of silver nitrate used in preparing the emulsion and in the case of the other sulfur sensitizers, an amount equal to from about 0.01 to about 10 g. per kilogram of the silver nitrate used in preparing the emulsion
• digest i. e. to heat treat, the emulsion withboth the water-insoluble gold compound and the sulfur sensitizer or thiocyanate present, at an appropriate temperature, e. g. at from 100 to 150 F.
• the pH of the emulsion is advantageously adjusted to between 5 and 7.
• Typicalwater-insoluble gold compounds with which photographic silver halide emulsions can be sensitized by digesting the emulsions in the presence thereof are described in the following examples.
• the procedures e. g. pH, temperature, sulfur sensitizers, thiocyanates, etc.
• sensitizing emulsions with water-soluble gold compounds can be employed.
• EXAMPLE 5 A solution containing 0.33 g. of auric chloride in 10 cc. of ethyl alcohol was added to cc. of 95% ethyl alcohol containing 0.85 g. of 3-ethyl- 2-(3) -thiothiazolo[4,5-bl quinolinone (prepared by heating 3-ethy1rhodanine and o-aminobenzaldehyde in acetic acid solution according to Granacher et al.-Helv. Chim. Acta 8, 890 (1925)). The above-formulated compound precipitated and after the reaction mixture stood for several hours at 20 C'., the product was collected on a filter and washed with 95% ethyl alcohol. The yield of light cream crystals was 75% after one recrystallization from acetic acid.
• a solution containing 0.34 g. of auric chloride in 10 cc. of 95% ethyl alcohol was added to a EXAMPLE '7 .
• a solution containing 0.5 g. of auric chloride in- 10 cc. of 95% ethyl alcohol was added to a hot suspension of 1.61 g. of'3-ethyl- -(3 ethyl- 12(3)-benzothiazolylidene) rhcdanine in '25 ccmot' acetic acid.
• the reaction mixture was .stood several hours at about 20 C.
• Sensitizing dyes of all types can be employed to spectrally (optically) sensitize my new stabilized emulsions, e. g. erythrosin, Congo Red, any of the sensitizing cyanine dyes (monomethine, trimethine, pentamethine, heptamethine, etc.), and any of the sensitizing merocyanine dyes (see United States Patent 2,078,233, dated April 27, 1937 for example), any of the sensitizing hemicyanine dyes (see United States Patent 2,166,736, dated July 18, 1939, for example), any of the sensitizing hemioxonol dyes (see United States Patent 2,216,441, dated October 1, 1940 and United States Patent 2,165,339, dated July 11, 1939, for example), etc.
• My new stabilized emulsions can be coated in the usual manner on any suitable support, such as glass, cellulose nitrate film, cellulose acetate film, polyvinyl acetal resin film, etc. to desired thickness, and then set in the usual manner. Hardening agents, setting agents and supersensitizing combinations of sensitizing dyes or a supersensitizing combination of one or more sensitizing dyes and another substance can be added to the emulsions.
• Emulsions in which the carrier for the silver halide is other than gelatin and which have been sensitized by digesting in the presence of a gold compound can be stabilized in accordance with my invention.
• non-gelatin silver halide emulsions are silver halide emulsions prepared using as the vehicle or carrier polyvinyl .alcohol (polyvinyl alcohol is herein intended to include all water-soluble hydrolyzed polyvinyl esters containing an ester group content equivalent to from to by weight of polyvinyl ester) silver halide emulsions prepared using as the vehicle or carrier hydrolyzed polyvinyl acetate containing an acetate group content equivalent to from 59 to 71% by Weight of polyvinyl acetate; silver halide emulsions prepared using as the vehicle or carrier polyvinyl acetals containing a large proportion of polyvinyl alcohol hydroxyl groups, e.
• polyvinyl acetaldehyde acetals containing polyvinyl acetaldehyde acetal group equivalent to at least 50% by weight of polyvinyl acetaldehyde acetal and polyvinyl alcohol hydroxyl groups equivalent to at least by Weight of polyvinyl alcohol, polyvinyl propionaldehyde acetals containin polyvinyl alcohol h droxyl groups equivalent to from to by weight of polyvinyl alcohol, and polyvinyl bucarrier in preparing my non-gelatin silver halide.
• any other resinous or 001- loidal material soluble in any ethylalcohol-water mixture or in water can be employed in preparing my non-gelatin silver halide emulsions, e, g. soluble polyamide resins, such as described in United States Patent 2,384,072, dated September 4, 1945, and hydrolyzed copolymers of vinyl estersand ethylene-or 12 propylene, such as described'in United States Patent 2,397,866, dated April 2, 1946.
• Any cellulose compound especially those containing only carbon, hydrogen and oxygen atoms, or those containing only carbon, hydrogen, oxygen and amino nitrogen atoms or ammonium nitrogen atoms, which is soluble in a mixture of ethyl alcohol and water (containing from 0 to 50% by volume of ethyl alcohol) to the extent of 10 g. per g. of solvent can be employed as the vehicle or carrier in preparing my non-gelatin silver halide emulsions.
• the silver halide emulsions can be prepared using gelling agents, such as phenols, e. g. orcinol, gallic acid, 2,4-dihydroxybenzoic acid, 4-chlororesorcinol, a-naphthol, phloroglucinol, 2,7-dihydroxynaphthalene, etc.
• the non-gelatin silver halide emulsions can be prepared using silver halide dispersing agents, e. g.
• starch acetate starch acetate, gum arabic, a copolymer of maleic anhydride and vinyl acetate, low viscosity methyl cellulose, water-soluble amino carbohydrate dispersing agents (e. g. diethanolamine cellulose acetate or any, other of these agents described in United States Patent 2,360,238, dated October 10, 1944) amino resin dispersin agents (e. g.
• dimethylaminobenzaldehyde acetals of polyvinyl alcohol or Water-soluble polyvinyl acetals in which at least a part of the acetal groups are 4-formylphenyltrialkylammonium salt acetal groups, such as the polyvinyl acetal of 4-formylphenyl trimethylammonium methylsulfate and other such compounds described in United States Patent 2,358,836, dated September 26, 1944), etc.
• Non-gelatin proteins can also be employed as vehicles or carriers in preparing the silver halide emulsions which are stabilized in accordance with my invention.
• Proteins such as casein, soybean protein, blood albumin, egg albumin, castor bean protein, globulin and edestin are examples of such non-gelatin proteins.
• Non gelatin proteins which have been converted to a derivative thereof, e. g. by reaction with a sulfonyl chloride, a carboxylic chloride, a carboxylic anhydride, an isocyanate, a 1,4-diketone or acrylonitrile, and then oxidized, e. g. with hydrogen peroxide, can also be employed.
• Myinvention is directed. especially to the stabilization of photographic silver halide emulsions which have been sensitized by digestion in the presence of at least one gold compound (watersoluble or water-insoluble) and in which the silver halide is principally silver bromide, but can be employed with any silver halide emulsion which has been so sensitized, particularly with the customary silver chloride, silver chlorobromide, silver chlorobromoiodide, silver chloroiodid'e, silver bromide and silver bromoiodide .de-.-'
• a process for stabilizing against loss of speed a photographic gelatino-silver-halide developing-out emulsion which has been sensitized by digesting the emulsion in the presence of a gold compound comprising adding to the goldcompound-sensitized emulsion after the final digestion of the emulsion, but prior to coating the emulsionona supper-ta water-soluble gold compound which has a solubility in water greater than the equivalent of v 1.0 mg. of gold per 100 ml. of water 'at' 25 C.
• a process for stabilizing against loss of :speed --a photographic gelatinmsilver-halide developing-out emulsion which has been sensitized flby...di'gesting the emulsion in the presence of a gold compound comprising adding to the-goldcompound-sensitized cemulsion, :at .a :pH of irom I 5 to 9, after the final digestion of the emulsion, .zbut prior to coating the emulsion ion a support, a water-soluble gold compound which has asolubility Lin-water greater than the equivalent of 1.0 mg. of gold per 100 ml. of water at 25 C.
• tized by digesting the emulsion in the presence of a ,goldcompound comprising addin to the ,goldcompound-sensitized emulsion at a pH of from 5 to 9, after :the final :digestion of the emulsion, but prior to coating the emulsion on a support, a water-soluble gold compound which has a .solub'i'lity in water greater than the equivalent of 1.0 mg. of gold per 100 ml. of water at 25 C., the concentration of the water-soluble gold compound being equivalent to from 1.5 to 20 mg. of gold per 1000 g. of silver nitrate used in preparing the emulsion.
• a process for stabilizing against loss of speed a photographic gelatino-silver-bromoiodide developing-out emulsion in which the silver halide is principally silver bromide, which has been sensitized by digesting the emulsion in the presence of a gold com-pound comprising adding to the gold-compound-sensitized emulsion at a pl-I of from 5 to 9, after the final digestion of the emulsion, but prior to coating the emulsion on "a welop'ing-ioutemulsions which :haveibeen .so sensi- 1114 support, :a' rwasteresoluble :gold compound.
• :sens'itizer nomprising adding to the tgoldecompoundesensitized .ennrlsion salt a pH v.oi from 5 to 9, :after thelfinal digestionof the emulsion, but prior to coating the .-.emulsion on :a :support, a water-soluble sgold compound which has :a solubility in water greater than the equivalent of 1.0 mg. of gold per 1003:1111. of-meter :at 25 (1., the .concentration aof fiche wateresoluble gold compound being equivalent "to from 1.5 to 20 mg. of gold per 1000 g. of silver nitrate .used in preparin the emulsion.
• a water-soluble gold compallysilver bromide which has been sensitized by digesting the emulsion in the presence of ;
• a gold compound and a thiocyanate selected from the group consisting of alkali metal and ammonium thiocyanates, comprising adding to the goldcomp'ound-sensitized emulsion at a pH of from 5 'to 9, after the final digestion of the emulsion, but prior to coating the emulsion on a support, a water-soluble gold compound which has a-solubility *inwater greater than the equivalent of 1.0 mg.-of gold per 100ml.
• Aprocessfor-stabilizing against loss-of speed a photographic gelatino-si1ver-brom0iodide 'developing-out emulsion in which the silver halide :is pr'incipa11-y silver bromide, whichhas been sensitized by digesting the emulsion in the presence of a gold compound and a thiocyanate selected from the group consisting of alkali metal and ammonium thiocyanates, comprising adding to the gold-compound-sensitized emulsion at a pH of from 5 to 9, after the final digestion of the emulsion, but prior to coating the emulsion on a support, a water-soluble gold compound which has a solubility in water greater than the equivalent of 1.0 mg. of gold per 100ml. of water at C., the concentration of the Water-soluble gold compound being equivalent to from 1.5 to 20 mg. of gold per 1000 g. of silver nitrate used in preparing the emulsion.
• potassium chloroaurate in a concentration of from 1.5 to 20 mg. of gold per 1000 g. of silver nitrate used in preparing the emulsion.
• a process for stabilizing against loss'of speed a photographic gelatino-silver-bromoiodide developing-out emulsion in which the silver halide is principally silver bromide, which has been sensitized by digesting the emulsion in the presence of potassium chloroaurate, thiosinamine and sodium thiocyanate comprising adding to the potassium-chloroaurate-sensitized emulsion at a pH of 5 to 9, after the final digestion of the emulsion, but prior to coating the emulsion on a support, potassium aurithiocyanate in a concentration of from 1.5 to 20 mg. of gold per 1000 g. of silver nitrate used in preparing the emulsion.

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  • BE BE498287D patent/BE498287A/xx unknown
• 1949
  • 1949-09-24 US US117719A patent/US2597856A/en not_active Expired - Lifetime
• 1950
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