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
  • G03C5/00—Photographic processes or agents therefor; Regeneration of such processing agents
  • G03C5/26—Processes using silver-salt-containing photosensitive materials or agents therefor
  • G03C5/40—Chemically transforming developed images
  • G03C5/46—Toning
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09B—ORGANIC DYES OR CLOSELY-RELATED COMPOUNDS FOR PRODUCING DYES, e.g. PIGMENTS; MORDANTS; LAKES
  • C09B50/00—Formazane dyes; Tetrazolium dyes
  • C09B50/02—Tetrazolium dyes
• • 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
  • G03C5/00—Photographic processes or agents therefor; Regeneration of such processing agents
  • G03C5/56—Processes using photosensitive compositions covered by the groups G03C1/64 - G03C1/72 or agents therefor

Definitions

• a zero valent metal image in which the metal has a standard oxidation potential more positive than -0.98 volt is advantageously replaced by a formazan dye by the single process step of contacting the metal image with a solution of a ligand in the presence of a tetrazolium salt when the combination of tetrazolium salt and ligand with water and zero valent metal produces a solution reaction potential E greater than -0i0l volt, the process forming a good dye image when the formazan dye is nondiifusible and the process blixing the metal image when the formazan dye is diffusible and the metal-ligand complex is diffusible.
• Compositions of tetrazolium salt and ligand are advantageously used in this single step process for dye image formation or for blixing a metal image.
• substantially all of a metal image is converted to (i.e., replaced by) a nondiffusible formazan dye image by contacting said metal image with an aqueous solution of a ligand that forms a soluble and diffusible metal complex in the presence of a T-salt and substantially all of the metal image is complexed without the need for a separate bleach step followed by a washing step and a separate fix step as is required by the prior art.
• Our process can advantageously be used to replace at least a part or all of a metal image with a formazan dye image.
• Water-soluble and diffusible T-salts i.e., a T-salt whose solution will pass freely to said metal image when it is in a colloid layer
• This invention is related to photography, compositions for 5 use in photographic processing, photographic processes for forming dye images and processes for the removal of metal images and metal salts from a color-developed color photographic l ment. 7
• silver images and dye images are formed during the color development step or steps, and it is desired to, remove the silver image and any residual silver halide so that the processed element will contain only the dye images and will not be subject to the formation of printout of silver from residual silver halide upon prolonged exposure to viewing light.
• the silver image is usually bleached, i.e., converted to a silver salt by treating it, for example, with a solution of alkaline metal ferricyanide in the presence of bromide ions, and then subsequently treating the silver salt with a silver salt complexing agent, such as an alkaline metal thiosulfate solution to convert the silver salt into a water-soluble, diffusible complex which is readily removed by washing the photographic element; 25
• the silver andresidual silver halide can be removed by using a blix, i.e., combined bleach-fix solution.
• a blix i.e., combined bleach-fix solution.
• farmers Reducer formed by combining a solution of watersoluble ferricyanide and a water-soluble thiosulfate, is a strong blix; however, it has a very short life and, for this reason, is not practical for many color processing applications.
• Other wellknown blixes use, as an oxidizing or bleaching agent, a ferric ion EDTA complex with a thiosulfate fixing agent. Although E (EM- M Formf-ult) this type of blix is.
• 908,299 describes a process for converting a silver image in a photographic emulsion layer into a formazan dye image by treating the silver image with a tetrazolium salt in the presence of cyanide ions, and subsequently bleaching with a ferricyanide bromide bleach bath, followed by washing, fixing with a sodium thiosulfate bath, washing and drying.
• cyanide ion is very undesirable because of 50 the danger to the operating personnel.
• the process described by the British patent requires a separate, additional bleach, fix and three intermediate washing steps in order to remove the silver image left after forming the formazan dye image.
• compositions comprising (1) a water-soluble and diffusible T-salt that is reduced by metal to form a water-soluble and diffusible formazan dye and (2) a water-soluble and diffusible metal complexing agent that forms a water-soluble and diffusible metal complex, are dissolved in water to make blix solutions that are valuable for removing silver and silver halide from colordeveloped color photographic elements.
• the solution reaction potential E is defined as follows:
• a and b are each integers of from 1 to 3 determined by the stable oxidation state of metal ion and which are needed to satisfy the stoichiometric relationship of the reaction of metal with T-salt; d represents the number of electrons transferred in said reaction;
• Standard oxidation potentials are the standard oxidation potentials for (1) zero valent metal to metal ion of valence m and (2) formazan dye to T-salt, respectively, [m"' [Formazan], [T-salt] and [11*] represent the concentrations of the indicated material.
• Standard oxidation potentials are for unit activity at 25 C. as referred to the hydrogen-hydrogen ion couple as zero volts. (See Handbook of Chemistry & Physics, 41st Edition, page 1,733 1959).)
• the water-soluble, diffusible tetrazolium salts used to advantage according to our invention are represented by the follquias stnsla iw It is therefore an object of our invention to provide a novel e i e blix composition which is stable and is valuable for use in 1 I (X color photographic processing. N
• Another object of our invention is to provide a novel process for removing silver and residual silver halide from a 9 9P? pl etsstsnh ssla sut.. ..W... Q
• Another object of our invention is to provide a novel process for converting a metalimage to a formazan dye image and, simultaneously, to remove the metal image from a blackand-white d ys snsqpb tqseahieslsmsma I I,
• Still another ob ect of our invention 18 to provide a novel composition which is valuable for the conversion of a silver image into a formazan dye image and, simultaneously, to remove the silver image in a single processstep.
• R, and R each represent a group such as an aryl
• a phenyl group e.g., phenyl, tol'yl, butylphenyl, a plished by the preparation and use of of our novel combinahydroxyphenyl group, an alkali metal or ammonium salt of Carboxyethylphenyl, a carboxyethylphenyl group, an ethoxycarbonylphenyl group, an aminophenyl group, a carbamylphenyl group, a sulfoethylphenyl group, an alkali metal or ammonium salt of a sulfophenyl group, a sulfonamidophenyl group, a sulfamylphenyl group, a mercaptophenyl group, a nitrophenyl group, etc.), a naphthyl group (e.g., a phenyl group (e.g.,
• substituents R and R can advantageously contain an electronsharing group capable of forming metal chelates or complexes, such as primary, secondary and tertiary amino, substituted amino, oxime, thioether, keto, thioketo, hydroxyl, mercapto, carboxyl, carboxyl, sulfo, phospho, alkoxy groups or complexes;
• X represents an anion (e.g., chloride, iodide, bromide, sulfate, paratoluenesulfonate, methylsulfate, ethylsulfate, nitrate, acetate, perchlorate, perborate, sulfite, hydroxide, carbonate, etc.);
• D represents a divalent aromatic group (e.g., a phenylene, diphenylene, naphthalene, phenylmethylphenyl, etc.); and E represents a divalent divalent
• any tetrazolium salts that are not shown specifically in the prior art are advantageously prepared by methods well known i n the art.
• V When aqueous solutions of our T-salts, brought into contact with metal images of palladium or any metal more easily oxidized (i.e., has a standard oxidation potential more positive than 0.98 volt) (e.g., silver, nickel, copper, iron, palladium, zinc, lead, tin, etc.), the metal is oxidized to its ion and the T- salt is reduced to produce the corresponding formazan dye.
• the following equation shows a typical reaction.
• Any ligand that is a silver complexing agent is advantageously used that produces a silver ion complex with a cumulative equilibrium constant B i.e.,
• a silver complexing agent is employed that produces with silver a complex with a B value that that is less than about l0 which is about 10" times smaller than the B of 10 for silver ions complexed with cyanide ions.
• a diffusible metal complex we mean a metal complex that in water solution can pass freely through photographic silver halide emulsion layers.
• ligands used to advantage are the following typical examples: water-soluble thiosulfates (e.g., sodium thiosulfate, potassium thiosulfate, ammonium thiosulfate, etc.), thiourea, ethylenethiourea, a water-soluble thiocyanate (e.g., sodium thiocyanate, potassium thiocyanate, ammonium thiocyanate), a water-soluble sulfur containing dibasic acid.
• water-soluble diols used to advantage include those having the formula:
• p is an integer of from 2 to 13; the 2's represent oxygen or sulfur atoms such that at least one-third of the Z atoms are sulfur and there are at least two consecutive Zs in the structure of the compound which are sulfur atoms.
• the diols advantageously used are also included in compounds having the formula:
• X and X represent oxygen or sulfur, such that when X represents oxygen, X represents sulfur and when X represents sulfur, X represents oxygen;
• c, d, e, f and g each represent an integer of from 1 to 15, such that the sum of c-l-d-i-efl-g represents an integer of from 6 to 19, and such that at least one third of the total of all the Xs plus all the X"s represent sulfur atoms and at least two consecutive X's and/or X"s in the structure of the compound are sulfur atoms.
• Typical diols include the following:
• nonacosanediol HO(CH CH S) CH CH OCH CH SCH CH O(CH CH S),-,CH CH OH 10. 6,9, l 5,18-Tetrathia-3, l 2,2 l-trioxa-l,23-tricosanediol HOCH CH O(CH CH S) CH Cl-I O(CH CI-l S) CH CH OCH CH
• Water-soluble sulfur containing dibasic acids used to advantage include those having the formula:
• Typical illustrative examples include:
• concentration of the T-salt and the ligand in our compositions can be varied considerably, with an operable range of concentrations extending from the solubility limit of the T- salt and the solubility limit of the ligand down to a minimum concentration where the overall reaction potential for the specific T-salt, ligand and specific metal image just remains positive, usually above +0.01 volt.
• concentrations and the preferred concentration ranges are readily determined by methods well known in the art and
• the metal images that are advantageously treated with our T-salt ligand compositions are produced by any of the conventional image-forming methods and especially by photographic methods, using chemical developing-out materials, physical developing-out materials, etc.
• the metal image is advantageously made up of minute particles of metal in a binder, e.g., a hydrophilic colloid such as, gelatin or gelatin substitute, or made of a solid, continuous surface of metal.
• Example 1 Conversion of a Silver Image to a Formazan Dye Image
• Solution A is made by dissolving the following composition:
• Example 2 pH-lndependence and Solution Stability
• Solution B is made by dissolving a composition containing l of 2,3,5 ,-triphenyl-ZH-tetrazolium chloride and 10 g. of ammonium thiosulfate in water to make 100 ml. of solution.
• Example 3 Spectral Distribution of the Light Absorption of Image Formazan Dye vs. Image Silver
• a sample of the silver halide emulsion coated film described in Example 2 is flash-exposed, black-and-white developed, fixed, washed and dried as described in Example 2, The density of the silver image to red, green and blue light is recorded under Untreated Area" in Table 2.
• Solution C Upon treatment of the sample for 60 minutes at 75 F. in Solution C (see composition below), the initial silver image is converted to a brown formazan dye image whose density to red, green and blue light is recorded under Treated Area in Table 2.
• Solution C is made by dissolving a composition containing 1 g.
• Example 4 Mixtures of T-salts Are Used To Adjust Color Of Dye Image
• the obtained formazan dye images range in color from red to blue.
• Solution D is made by dissolving a composition containing 1 g. of 2- (4,5dimethylthiazd-2-yl)-3,5-diphenyl-2H-tetrazolium bromide and 10 g. of ammonium thiosulfate in water to make 100 ml. of solution having a pH of 8.0.
• Example 5 Silver Images In A Variety Of Photographic Materials Are Convertible'To Formazan Dye Images Black-and-white processed (i.e., developed, fixed, washed and dried as described in Example 1) samples of several types of negative type, developing-out photographic materials are treated from I to 16 minutes in portions of Solution B (see Example 2) ranging in pH from 6 to 12 to produce formazan dye images essentially as described in the preceding examples.
• the photographic materials include:
• a coarse-grain gelatinous silver bromoiodide X-ray film 2.
• a fine-grain gelatinous silver bromoiodide film 3.
• Example 7 Certain Organic Solvents Increase Rate Of Dye Formation
• Two black-and-white processed i.e., developed, fixed, washed and dried as described in Example 1) samples of a negative type, developing out fine-grain gelatinous silver chlorobromide emulsion Micro-File films are treated at 115 F. and pH 7.0 in Solutions E and F (compositions below), respectively, for 0, 15, 30, 60 and 120 seconds.
• the data recorded in Table 5 indicate that benzyl alcohol increases the rate of the conversion from image silver to formazan dye.
• Solution E is made by dissolving a composition containing 1 g. of 2,3,5-triphenyl-2I-I -tetrazolium chloride, 20 g. of ammonium thiosulfate and 0.1 g. of thiourea in water to make ml. of solution.
• Solution F is made by adding 0.4 ml. of benzyl alcohol to 100 ml. of Solution E.
• Solution E 180 30 l7 15 Solution F I80 46 l4 l0 8
• Example 8 Mixtures of Metal Complexing Agents Increase The Rate Of Dye Formation
• a first sample of a sensitometrically exposed, developed, fixed, washed and dried, negative type, developing-out, finegrain gelatinous silver bromoiodide emulsion coated film is treated at 75 F. for 2 minutes in Solution G (see composition below).
• Solution G is made by dissolving the following composition:
• a selectively balanced Blix composition according to our invention effectively removes the image silver from various types of processed photographic materials.
• the rate of silver removal increases with increased temperature.
• Silver images in several exposed, developed, fixed, washed and dried coarsegrain gelatinous silver halide X-ray films and a fine-grain gelatinous silver halide film are treated for various times at temperatures of 75 F., 100 F. and F. in portions of Solution B (see Example 2). These films are coated with negative type, developing out gelatinous-silver bromoiodide emulsions.
• the effect of temperature on the rate and amount of silver removal is illustrated by the data recorded in Table 7.
• Example l0 Formazan Dye images Are Sharper Than the initial Silver Images From Which They Are Derived time in A sensitornetrically exposed negative type, developing-out 2Q H coarse-grain gelatinous silver bromoiodide X-ray film is developed, fixed washed and dried as described in Example 1.
• One sample of this processed film is used as a control: a s 2min: 1,; second sample is treated for 4 minutes in Solution G (see Ex- Sample 4 4 min. 3.20 o. lb 2.0 ample 8) and a third sample is treated for 8 minutes in Solu- Sample 5 tion 0.
• the densities of the resulting images to blue light in each of the processed film samples are measured with a densitometer.
• Film mp9 second sample containing an identical nickel image is not treated in a Blix solution and served as a control.
• a comgss r' 8%; l'ig 1'28 parison between the sensitometric curves of the nickel image 3 8 in the untreated sample and the formazan dye image in the treated sample demonstrates the effective conversion of nickel to formazan dye in the blix solution according to our invention.
• Example 13 A Soluble-dye-forming T-salt Blixes Image These data show the increase in image density produced by treatment of film samples with Solution G. X-ray line exposures made on Film Samples 4, 5 and 6 as described in Rev. of 45 Scientific Instruments, 38, No. 11 pages l.6l9-1,622, Nov. 19, 1967 are processed as described for Samples 1, 2 and 3, Save w'thout Retfmtmn ofa Dye Image respectively, in this example.
• Example 14 The Forrnazan Image Dyes Generated By the Five samples of a coating of a direct-positive type, developing-out, gelatinous silver chlorobromoiodide emulsion are exposed to a graduated density test object and black-and-white developed to a direct positive image reproduction. "max,
• a first Sample of a "egatwe yp developmg'out -g soiuiion H is made by dissolving the f n i i i gelatinous silver bromoiodide emulsion coated film is flash-exposed, black-and-white developed to a silver density of 0.4
• Example 2 A composition is made like that in Example 2, but in which the ammonium thiosulfate is replaced by an equimolar amount of sodium thiosulfate. Examples 1 and 9 are then repeated, using the modified solution. Results are obtained that are similar to those obtained in Examples l and 9.
• EXAMPLE 18 An X-ray film like that described in Example 10 is exposed to an X-ray image, developed in a conventional X-ray film developer, fixed, washed and dried. Fifteen identical samples are taken of the processed X-ray film. One sample is used as a control, while the other samples are each treated by contacting with a different Solution K, L, M, N, O, P, Q, R, S, T, U, V and W (described below). The silver image in each of the treated samples is replaced by a formazan dye image corresponding to the particular T-salt used in the treatment solution of our invention. Solutions K through W are made, each containing 10 g. of ammonium thiosulfate per 100 ml. and l g. of the T-salt indicated in the table below:
• a photographic composition for converting a zero valent metal image into a formazan dye comprising (a) a soluble and diffusible tetrazolium salt and (b) a ligand which produces a silver complex having a smaller cumulative equilibrium constant of [3 than the complex of silver with cyanide ion, such that the combination of said tetrazolium salt and said ligand with a zero valent metal image in the presence of water produces a solution reaction potential of at least +0.01 volt.
• a photographic composition for converting a zero valent metal image into a formazan dye comprising (a) a water-soluble, diffusible tetrazolium salt represented by the formulas:
• R and R each represent a group selected from the class consisting of an aryl group and a heterocyclic group
• R represents a member selected from the class consisting of hydrogen, an alkyl group, an aryl group, a heterocyclic group, hydroxyl, carboxyl group, salt of carboxyl group, a carboxyester group, an amino group, a carbamyl group, sulfo, a slat of the sulfo group, a sulfonamido group, a sulfamyl group, the mercapto group and the nitro group
• X represents an anion
• D represents a divalent aromatic group
• E represents a divalent group selected from the class consisting of an alkylene group, an arylene group and an aralkylene group
• n represents an integer of from 1 to 5
• (b) a metal complexing agent which produces a silver complex having a cumulative equilibrium constant [3 that is at least 10 times less than said constant for
• a composition of claim 2 in which the metal complexing agent is selected from the class consisting of a water-soluble thiosulfate, thiourea, ethylenethiourea, a water-soluble thiocyanate, a water-soluble sulfur containing dibasic acid and a water-soluble diol containing sulfur atoms.
• composition of claim 2 in which the tetrazolium salt is 2,3,S-triphenyl-ZH-tetrazolium chloride.
• composition of claim 2 in which the tetrazolium salt is 2,3,5-tri( p-carboxyphenyl)-2H-tetrazolium bromide.
• composition of claim 2 in which the metal complexing agent is a water-soluble thiosulfate.
• a photographic composition comprising 2,3,5-triphenyl- ZH-tetrazolium chloride and ammonium thiosulfate, which combination with a zero valent metal image in the presence of water produces a solution reaction potential of at least +0.01 volt and which metal complexes are water soluble and diffusible.
• a photographic composition comprising 2,3,5-tri(p-carboxyethylphenyl)-2l-l-tetrazolium bromide and ammonium thiosulfate which combination with a zero valent metal image in the presence of water produces a solution reaction potential of at least +0.01 volt and which metal complexes are water soluble and diffusible.
• a photographic composition comprising 2-(benzothiazol- 2-yl)-3 -phenyl-5-(o-chlorophenyl)-2H-tetrazolium chloride and ammonium thiosulfate, which combination with a zero valent metal image in the presence of water produces a solution reaction potential of at least +0.01 volt and which metal complexes are water soluble and difi'usible.
• a photographic composition comprising 2-(4,5- dimethylthiazol-Z-yl)-3,5-diphenyl-2H-tetrazolium bromide and ammonium thiosulfate, which combination with a zero valent metal image in the presence of water produces a solution reaction potential of at least +0.01 volt and which metal complexes are water soluble and diffusible.
• a process for converting at least a portion of a zero valent metal image to a formazan dye image which comprises contacting said metal image with a water-soluble, diffusible ligand that forms a silver complex with a smaller cumulative equilibrium constant B than the complex of silver with cyanide ion, such that the combination of said metal, said tetrazolium salt, said ligand and water produces a solution reaction potential of at least +0.01 volt.
• a process of converting at least a portion of a zero valent metal image to a nondiffusible formazan dye image which comprises the step of contacting said metal image with an aqueous solution containing l) a water-soluble, diffusible tetrazolium salt represented by the formulas:
• R, and R each represent a group selected from the class consisting of an aryl group and a heterocyclic group
• R represents a member selected from the class consisting of hydrogen, an alkyl group, an aryl group, a heterocyclic group, hydroxyl, carboxyl group, salt of carboxyl group, a carboxyester group, an amino group, an amido group, a carbamyl group, sulfo, a salt of the sulfo group, a sulfonamido group,.a sulfamyl group, the mercapto group and the nitro group;
• X represents an anion;
• D represents a divalent aromatic group and E represents a divalent group selected from the class consisting of an alkylene group, an arylene group and an aralkylene group;
• n represents an integer of from 1 to 5; and (2) a metal complexing agent which produces a silver complex that has a cumulative equilibrium constant ⁇ 3 that is at least 10 times
• a single-step photographic process for converting at least a portion of a zero valent metal image in a hydrophilic colloid layer to a nondiffusible formazan dye image comprising the step of contacting said metal image with an aqueous solution containing (1) a water-soluble, diffusible tetrazolium salt and (2) a metal complexing agent which produces a silver complex having a cumulative equilibrium constant B that is at least 10" times smaller than said constant for the complex of silver with cyanide ion, such that the combination of said aqueous solution with said zero valent metal produces a solution reaction potential of at least +0.01 volt.
• a process for converting a silver image in a gelatin layer to a formazan dye image and removing silver and silver salts comprising the step of contacting said silver image with an aqueous solution containing 10 g. of 2,3,5-triphenyl-2H- tetrazolium chloride and 200 g. of ammonium thiosulfate per liter of solution.
• a process for converting a silver image in a gelatin layer to a formazan dye image and removing silver and silver salts comprising the step of contacting said silver image with an aqueous solution containing 10 g. of 2,3,5-triphenyl-2H- tetrazolium chloride, g. of ammonium thiosulfate, 10 g. of disodium phosphate, 0 to 0.8 ml. of benzyl alcohol, 0 to 0.1 of ethylene thiourea, 0 to 10 g. of thiourea per liter of solution.
• a process for converting a silver image in a gelatin layer to a formazan dye image and removing silver and silver salts comprising the step of contacting said silver image with an aqueous solution containing 3-phenyl-5-(o-chlorophenyl)- ZH-tetrazolium chloride and 100 g. of ammonium thiosulfate per liter of solution.
• a process for converting a silver image in a gelatin layer to a formazan dye image and removing silver and silver salts comprising the step of contacting said silver image with an aqueous solution containing 10 g. of 2-(4,5-dimethylthiazol-2- yl)-3,5-diphenyl-2H-tetrazolium bromide and 100 g. of ammonium thiosulfate per liter of solution.
• a process for converting a silver image in a gelatin layer to a formazan dye image and removing silver and silver salts comprising the step of contacting said silver image with an aqueous solution containing 1 g. of 2,3,5-triphenyl-2H- tetrazolium chloride, 0.2 g. of 2-(4,5-dimethylthiazol-2-yl)- 3,5-diphenyl-2H-tetrazolium bromide and 12 g. of ammonium thiosulfate per ml. of solution.

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• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
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Citations (3)

• 1970
  • 1970-02-25 US US14228A patent/US3642478A/en not_active Expired - Lifetime
• 1971
  • 1971-02-23 FR FR7106041A patent/FR2078932A5/fr not_active Expired
  • 1971-02-24 BE BE763411A patent/BE763411A/xx unknown
  • 1971-04-19 GB GB2211871A patent/GB1333613A/en not_active Expired

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