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
  • G03C7/00—Multicolour photographic processes or agents therefor; Regeneration of such processing agents; Photosensitive materials for multicolour processes
  • G03C7/30—Colour processes using colour-coupling substances; Materials therefor; Preparing or processing such materials
  • G03C7/44—Regeneration; Replenishers
• • 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
  • G03C5/50—Reversal development; Contact processes

Definitions

• This invention relates in general to color photography and in particular to methods and compositions useful in the processing of color reversal photographic elements. More particularly, this invention relates to a bleach regenerator composition, and its use in the processing of the noted elements.
• Multicolor, multilayer photographic elements are well known in the art. Such materials generally have three different selectively sensitized silver halide emulsion layers coated on one side of a single support. Each layer has components useful for forming a particular color in an image. Typically, they utilize color forming couplers that form yellow, magenta and cyan dyes in the sensitized layers during processing.
• a commercially important process intended for use with color reversal photographic elements that contain color couplers in the emulsion layers, or layers contiguous thereto uses the following sequence of processing steps: first developing, washing, reversal bath, color developing, bleaching, fixing, washing and stabilizing.
• One known bleach regenerator solution for reversal color processes is sold by Tetenal of Germany (sold as Tetenal Bleachbath E6/E6AR BL-RCY), which has a pH of 7, and contains a relatively high bromide ion concentration (approximately 190-210 g/l).
• This invention also provides a bleach regenerator composition characterized as having a pH of from 6.0 to 6.5, and comprising a total bromide concentration of at least 210 g/l, and a complex of ferric ion and ethylenediaminetetraacetic acid, the ferric ion being present in an amount of at least 50 g/l.
• a pH adjusted regenerated bleach replenisher composition comprises a ferric complex of ethylenediaminetetraacetic acid and having a pH of from 5.4 to 5.6,
• the present invention effectively provides a bleach regenerator composition and bleach replenisher for processing reversal color silver halide photographic materials.
• the bleach regenerator composition is more stable and stays in solution even at lower pH for extended periods of time.
• the composition is highly concentrated, for example, in the ferric ion concentration, so that more bleach overflow can be used to form the bleach replenisher.
• Reversal color photographic elements utilized in the practice of this invention are typically comprised of a support having on one side thereof a plurality of photosensitive silver halide emulsion layers.
• the photosensitive layers can contain any of the conventional silver halides as the photosensitive material, for example, silver chloride, silver bromide, silver bromoiodide, silver chlorobromide, silver chloroiodide, silver chlorobromoiodide, and mixtures thereof.
• Useful support materials include cellulose acetate film, polyvinylacetal film, polycarbonate film, polystyrene film, polyethylene terephthalate film, and the like.
• the silver halide is dispersed within a suitable hydrophilic colloid such as gelatin or derivatives thereof.
• the silver halide emulsion layers can contain a variety of well-known addenda, including but not limited to, chemical sensitizers, development modifiers and antifoggants.
• a well-known color reversal process of the prior art utilizes a first developer, a reversal bath, a color developer, a conditioning solution, a bleach bath, a fixing bath and a stabilizer bath.
• the stabilizer bath can be replaced with a typical wash or rinse solution, and a "prebleach" or “conditioner” bath is used for stabilizing the color image after color development and prior to bleaching.
• the components that are useful in each of such baths are well known in the photographic art.
• the improved process of this invention can utilize the same baths.
• the first developer generally contains a black-and-white developing agent or a mixture thereof.
• useful developing agents include, but are not limited to, dihydroxybenzene developing agents (such as hydroquinone), 3-pyrazolidone developing agents (such as 1-phenyl-3-pyrazolidone), and aminophenol developing agents (such as paraaminophenol).
• the first developer typically contains other agents such as preservatives, sequestering agents, restrainers, antifoggants, buffers and silver halide solvents.
• the reversal bath generally contains a nucleating agent, such as a boron compound or a chelated stannous salt (such as stannous chloride) that functions as a reducing agent, as well as antioxidants, buffers, fungicides and sequestering agents.
• a nucleating agent such as a boron compound or a chelated stannous salt (such as stannous chloride) that functions as a reducing agent, as well as antioxidants, buffers, fungicides and sequestering agents.
• the color developing bath typically contains sequestering agents, buffering agents, preservatives, antioxidants, competing couplers and silver halide solvents.
• aromatic primary amino color developing agents are the p -phenylenediamines and especially the N,N-dialkyl- p -phenylenediamines in which the alkyl groups or the aromatic nucleus can be substituted or unsubstituted.
• Examples of useful p -phenylenediamine color developing agents include, but are not limited to, N,N-diethyl- p -phenylenediamine monohydrochloride, 4-N,N-diethyl-2-methylphenylenediamine monohydrochloride, 4-(N-ethyl-N-2-methanesulfonylaminoethyl)-2-methylphenylenediamine sesquisulfate monohydrate, 4-(N-ethyl-N-2-hydroxyethyl)-2-methyl-phenylenediamine sulfate, 4-N,N-diethyl-2,2'-methanesulfonylaminoethylphenylenediamine hydrochloride, and others readily apparent to a skilled worker in the art.
• the essential component of the bleaching bath is a bleaching agent that converts metallic silver to silver ions.
• Other common components of the bleaching bath include halides, sequestering agents and corrosion inhibitors.
• One or more ammonium or alkali metal salts of a ferric complex of ethylenediaminetetraacetic acid are useful as bleaching agents in this invention.
• the fixing bath converts all silver halide into soluble silver complexes that diffuse out of the emulsion layers. Fixing bath retained within the layers of the photographic element is removed in a subsequent water washing step. Thiosulfates, including ammonium thiosulfate and alkali metal thiosulfates (such as sodium thiosulfate and potassium thiosulfate), are particularly useful as fixing agents. Other components of the fixing bath include preservatives and sequestering agents.
• a wide variety of different color reversal processes are well known in the art.
• a single color developing step can be used when the coupling agents are incorporated in the photographic element or three separate color developing steps can be used in which coupling agents are included in the developing solutions.
• the reversal step can be carried out by use of a reversal bath, by a reexposure step, or by incorporating a fogging agent in the color developing bath.
• bleaching and fixing can be combined in a single step (known as a bleach-fixing step).
• Stabilization solutions are also known in the art for use in reversal photoprocessing methods. Such solutions generally include formaldehyde or an equivalent material to stabilize magenta dye image. Further details of such solutions are provided, for example, in US-A-4,786,583.
• stabilization is achieved by using a prebleach or conditioning solution after color development and prior to bleaching.
• a prebleach or conditioning solution after color development and prior to bleaching.
• the various details of such solutions and their use are provided, for example, in US-A-4,921,779, US-A-4,975,356, US-A-5,037,725, and US-A-5,334,493.
• Other optional features of useful conditioning solutions are secondary amines.
• the bleaching composition used in this invention comprises a complex of ferric ion and ethylenediaminetetraacetic acid in a suitable concentration.
• the amount of iron(III) is generally from 50 to 58 g/l.
• One or more salts of the complex can be used if desired.
• the bleaching composition is supplied to the bleach tank in a suitable rate to result in an overflow of used bleaching solution from the bleaching tank. Generally, the rate of supply is less than or equal to 215 ml/m 2 , and preferably from 140 to 215 ml/m 2 .
• At least 50%, preferably from 50 to 80%, and more preferably from 50 to 75%, of the bleaching - composition overflow is mixed with the bleach regenerator composition to obtain a regenerated bleach replenisher.
• the mixing is carried out in at least a 1:1 volume ratio of bleaching composition overflow to bleach regenerator composition, and up to 9:1.
• the volume ratio of mixing is from 1:1 to 3:1.
• the pH of the regenerated bleach replenisher is adjusted downward to from 5.4 to 5.6 by adding a suitable amount of an organic or inorganic acid, such as acetic acid, succinic acid, maleic acid, tartaric acid, malonic acid, or nitric acid.
• an organic or inorganic acid such as acetic acid, succinic acid, maleic acid, tartaric acid, malonic acid, or nitric acid.
• Acetic acid is preferred.
• the amount of acid to be added could be readily determined by routine experimentation, depending upon the pH of the regenerated bleach replenisher and the particular acid used.
• the amount added is generally from 10 to 20 ml/l.
• One advantage of this invention is that less acid needs to be added to the regenerated bleach replenisher than to conventional regenerator solutions.
• the pH adjusted regenerated bleach replenisher is then added to the bleaching tank as the "bleach replenisher" at a bleach replenishment rate of less than or equal to 215 ml/m 2 , and preferably at from 140 to 215 ml/m 2 .
• the bleach regenerator composition used in the method of this invention has a pH of from 6.0 to 6.5 (preferably from 6.0 to 6.2). It includes the bleaching agent, a ferric ion complex of ethylenediaminetetraacetic acid in an amount to provide ferric ion in an amount of at least 50 g/l, and preferably at from 50 to 58 g/l.
• Ferric ion can be supplied for the complex as a suitable ferric salt or oxide, such as ferric nitrate, ferric sulfate, ferric oxide or ferric bromide. Ferric oxide or ferric nitrate is preferred.
• the complex can be provided as an ammonium or alkali metal salt, as well as the free acid.
• total bromide ion is provided by a combination of hydrobromic acid and a bromide salt (such as sodium bromide, potassium bromide, ammonium bromide or lithium bromide). More preferably, at least 80%, more preferably from 80 to 97%, of the total bromide ion is provided from the bromide salt, and the remainder from the hydrobromic acid. Ammonium bromide is most preferred.
• One or more corrosion inhibitors can also be included in the bleach regenerator composition if desired at suitable concentrations.
• corrosion inhibitors include, but are not limited to, the potassium salts of nitrate, silicate, chromate and phosphate. Hexamethylenetetraamine and benzotriazole can also be used. Potassium nitrate is preferred.
• a preferred embodiment of this invention is a bleach regenerator composition having a pH of from 6.0 to 6.2, and comprising:
• the photographic elements processed in the practice of this invention can be single or multilayer color elements.
• Multilayer color elements typically contain dye image-forming units sensitive to each of the three primary regions of the visible spectrum. Each unit can be comprised of a single emulsion layer or multiple emulsion layers sensitive to a given region of the spectrum.
• the layers of the element can be arranged in any of the various orders known in the art.
• the emulsions sensitive to each of the three primary regions of the spectrum can be disposed as a single segmented layer.
• the elements can also contain other conventional layers such as filter layers, interlayers, subbing layers, overcoats and other layers readily apparent to one skilled in the art.
• a magnetic backing can be used as well as conventional supports.
• the present invention is particularly useful to process imagewise exposed and developed photographic elements containing arylpyrazolone type magenta dye forming color couplers.
• color couplers are well known in the art.
• One such compound is described in US-A-5,037,725.
• Useful cyan dye and yellow dye forming couplers that can be incorporated into such elements are also well known.
• the elements are typically exposed to suitable radiation to form a latent image and then processed as described above to form a visible dye image.
• the bleaching step described above is generally carried out for from 4 to 8 minutes, but longer times can be used if desired. Preferably, the bleaching time is 6 minutes.
• the temperature at which bleaching is carried out is generally above room temperature, for example from 30 to 40 °C.
• Processing according to the present invention can be carried out using conventional deep tanks holding processing solutions. Alternatively, it can be carried out using what is known in the art as "low volume thin tank” processing systems having either vertical rack and tank or horizontal automatic tray designs. Such processing methods and equipment are described, for example, in US-A-5,436,118 and publications cited therein.
• a preferred bleach regenerator composition of this invention was prepared by mixing the following in water (added to make 1 liter total): commercially available 1.56 molar ammonium ferricethylenediaminetetraacetic acid (788 g), hydrobromic acid (61.5 g), ammonium bromide (243.9 g) and potassium nitrate (67 g). The final pH was 6.0-6.2.
• the bleach regenerator composition of Example 1 was mixed with seasoned conventional color reversal bleach composition overflow comprising 1.56 molar ammonium ferric-ethylenediaminetetraacetic acid bleaching agent (277 g/l), bromide ion from various salts (73.8 g/l), and potassium nitrate (25 g/l).
• the volume ratio of bleach composition (which is comparable to bleach overflow) to bleach regenerator composition was 1:1.
• the resulting regenerated bleach replenisher had a pH of 5.95-6.1.
• the pH was then adjusted downward to 5.4-5.6 by adding acetic acid (18 ml/l) to provide a pH adjusted regenerated bleach replenisher that can be directly added to a bleach bath to process reversal color silver halide photographic materials.
• the amount of acetic acid needed to adjust the pH of the regenerated bleach replenisher was only 18 ml/l.
• the commercially available Tetenal Bleachbath E6/E6AR BLRCY regenerator solution was used in a similar fashion, it was necessary to add acetic acid at 30 ml/l in order to obtain the desired pH.
• the present invention allows one to reduce the amount of acid in preparing a bleach replenisher, and this acid reduction provides advantages as noted above.
• the regenerated bleach replenisher compositions of this invention were evaluated in otherwise conventional reversal color photographic processing.
• the invention was used to process samples of a conventional color reversal photographic films (available from Eastman Kodak Company) using the following processing protocol.
• This film contained a conventional 1-aryl-5-pyrazolone magenta color coupler in one of the emulsion layers.
• Processing Protocol 6 minutes First Development* 2 minutes Water wash 2 minutes Reversal bath** 6 minutes Color development*** 2 minutes Prebleach @ 6 minutes Bleaching**** 4 minutes Fixing # 4 minutes Water wash 30 seconds Final wash ## 20 minutes Drying * Using conventional Process E-6 KODAKTM First Developer. ** Using conventional Process E-6 KODAKTM Reversal Bath. *** Using conventional Process E-6 KODAKTM Color Developer. @ Using conventional Process E-6 KODAKTM Prebleach and Replenisher. **** Using conventional Process E-6 KODAKTM Bleach (Ferric-EDTA bleaching agent). # Using conventional Process E-6 KODAKTM Fixer. ## Using conventional Process E-6 KODAKTM Final Rinse.
• the method of this invention was carried out by taking at least 50% of the bleach bath overflow and mixing it (at a 1:1 volume ratio) with the bleach regenerator composition of Example 1. This mixing was °carried out for 3 minutes at 20-25 °C in a separate vessel. The mixture pH of 5.9-6.1 was then adjusted downward by adding acetic acid as described in Example 2, and the adjusted mixture was then added to the bleach bath as a replenisher for the process. This method was carried out for at least 4 bleach tank turnovers, or for at least 330 m 2 of processed reversal color photographic film. The results of processing were highly acceptable. That is, use of the noted regenerated bleach composition provided highly acceptable processing of the film.
• regenerator compositions like that described in Example 1 above were subjected to keeping tests to see if crystallization or precipitation would occur.
• the various compositions had components like Example 1 and various pH values as shown in Table I below.
• Table I The results of the keeping tests are shown in Table I for the various compositions.
• Column 1 lists the keeping temperatures (from -18 to +21 °C) at which the compositions were stored for 14 days.
• Column 2 shows when the crystallization results were observed (at room temperature) after the compositions were removed from the keeping environment, that is "Observation Time After Removal”. Thus, samples of each composition were observed immediately ("0" time), 24 hours, and 11 days after they were removed from the keeping environment. Crystals of ammonium ferric ethylenediaminetetraacetic acid complex were measured by visual inspection and identified by Fourier Transform Infrared (FTIR) spectroscopy.
• FTIR Fourier Transform Infrared
• Control D was a commercial Process E-6 (reversal) Bleach Replenisher containing ferric ethylenediaminetetraacetic acid bleaching agent and having pH 5.4.
• Control E was a commercial highly concentrated (1.56 mol/l) ammonium ferric ethylenediaminetetraacetic acid, KODAK BL-1, having pH 7.0.
• Examples 4 and 6 and Control C were formulated into working strength bleaching solutions, and were then used to bleach three different commercially available reversal color films: KODAK EKTACHROMETM 400 HC Film, KODAK EKTACHROMETM ELITETM 100 Film and KODAK EKTACHROMETM 64 Professional Film.
• Bleach replenisher provides three benefits to the tank bleaching solution:
• the conventional Tetenal Process E-6 bleach regenerator has bromide ion levels which account only for the first and third benefits noted above. We have found that this is inadequate, and that the level of bromide ion in the bleach regenerator must also be adjusted for bromide ion used up in the bleaching reaction (approximately 14-18 g/l of replenisher when processing elements containing 4.3-5.4 g silver/m 2 ). Thus, we determined that the level of bromide ion needed to be increased in the regenerator composition that is used to provide a regenerated bleach replenisher, and the present invention reflects that fact.

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• 1996
  • 1996-10-25 DE DE1996606377 patent/DE69606377T2/de not_active Expired - Fee Related
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