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
  • G03C8/00—Diffusion transfer processes or agents therefor; Photosensitive materials for such processes
  • G03C8/42—Structural details
  • G03C8/52—Bases or auxiliary layers; Substances therefor

Definitions

• This invention relates to photography, and more particularly to black-and-white and color diffusion transfer photography wherein a stripping layer with adjacent hydrophilic layers, one of which contains particulate material in a certain amount, is employed to enable an image-receiving layer to be cleanly separated from the rest of the assemblage after processing.
• the separated image-receiving layer has substantially none of the stripping layer adhered thereto.
• an alkaline processing composition permeates the various layers to initiate development of the exposed photosensitive silver halide emulsion layers.
• the emulsion layers are developed in proportion to the extent of the respective exposures, and the image dyes which are formed or released in the respective image generating layers begin to diffuse throughout the structure. At least a portion of the imagewise distribution of diffusible dyes diffuses to the dye image-receiving layer to form an image of the original subject. The user does not have to time this process.
• a problem with the integral assemblages described above is that the silver halide and other imaging layers, the spent pod which originally contained processing fluid, and the trap which retains excess processing fluid remain with the print after processing.
• the resulting prints are bulky and are somewhat difficult to stock or store in albums.
• Peel-apart formats for color diffusion transfer assemblages have previously been described, for example, in U.S. Patents 2,983,606, 3,362,819 and 3,362,821.
• the image-receiving element must be separated from the photosensitive element after a certain amount of time has elapsed, usually about one minute. This requires the customer to time the process which may be a disadvantage if a clock is not available.
• the portion of the assemblage to be discarded is wet with caustic processing fluid, and care must be taken with its handling.
• U.S. Patent 3,730,718 relates to diffusion transfer assemblages wherein a stripping layer is employed so that an image-receiving layer may be separated from a light-sensitive element during development.
• a stripping layer is employed between layers, both of which contain particulate material.
• assemblages wherein particulate material is present in layers on both sides of a stripping layer exhibit nonuniform fracture of the stripping layer upon separation, with the dis- advantages as described below.
• U.S. Patent 4,359,518 also relates to diffusion transfer assemblages wherein a stripping sheet is employed in conjunction with a release layer to effect stripping a photosensitive layer from a film unit after processing.
• Particulate material such as silica particles are employed in a timing layer of the stripping sheet to prevent blocking and to function as an antistatic agent.
• a release layer is employed between a silver halide emulsion layer and a "protective layer", the composition of which appears to be unknown.
• This patent does not disclose the use of a hydrophilic layer located between the stripping layer and the silver halide emulsion layer and which contains particulate material as described herein.
• the object of the present invention is to provide a photographic assemblage comprising
• each side of the stripping layer has a hydrophilic layer immediately adjacent thereto, other than a photosensitive silver halide emulsion layer or an image-receiving layer, and only one of the hydrophilic layers contains particulate material substantially insensitive to light and in a volume percentage of 5 to 75 percent of the hydrophilic material-particulate material mixture in that layer, so that upon separation, substantially all of the stripping layer will remain with the portion of the assemblage having the hydrophilic layer containing the particulate material.
• the hydrophilic layer which contains the particulate material is located between the stripping layer and the silver halide emulsion layer so that upon separation, substantially all of the stripping layer will remain with the portion of the assemblage containing the silver halide emulsion layer.
• the exposed photosensitive element is developed.
• a silver halide complexing agent dissolves the silver halide and transfers it to the image-receiving layer.
• Silver precipitating nuclei in the image-receiving layer then cause the transferred silver halide complex to be reduced to silver, thereby forming an image pattern corresponding to the original. Details of the process are well known to those skilled in the art as shown, for example, by U.S. Patents 3,220,835 and 3,820,999.
• the silver halide emulsion layer has associated therewith a dye image-providing material.
• any material may be employed as the stripping layer in the invention provided it has the required properties.
• Such materials are disclosed, for example, in U.S. Patents 3,220,835, 3,730,718 and 3,820,999 and include gum arabic, sodium alginate, pectin, polyvinyl alcohol and hydroxyethyl cellulose. In a preferred embodiment of this invention, hydroxyethyl cellulose is employed.
• stripping layer materials employed in this invention can be employed in any amount which is effective for the intended purpose. Good results have been obtaiqed at a concentration of from 5 to 2000 mg/m 2 of element. The particular amount to be employed will vary, of course, depending on the particular stripping layer material employed and the particular diffusion transfer element selected.
• the materials employed in the hydrophilic layers on each side of the stripping layer in this invention include any of the well known materials commonly used in the photographic art for such use. These materials include, for example, gelatin, polysaccharides, acrylamide polymers and other polymeric materials such as those disclosed in Research Disclosure, Vol. 176, December 1978, Item 17643, page 26. In a preferred embodiment of the invention, gelatin is employed.
• the coverage of the hydrophilic layer can be widely varied, as desired. Good results have been obtained at coverages ranging from 0.1 to 2.0 g/m 2 of element.
• the particulate material employed in the hydrophilic layers of the invention described above can be any material provided it produces the desired results of tightly bonding that layer to the adjacent stripping layer. Such material should not be light-sensitive since it would interfere with the imaging chemistry in the light-sensitive portion of the photosensitive element. Good results have been obtained with carbon black, such as Cabot Regal 400 * carbon black, average particle diameter 0.07pm and CITGO (Columbia) Carbon Raven 410°, average particle diameter 0.07 pm; titanium dioxide, such as Gulf and Western Horsehead° Rutile, average particle diameter 0.25 pm; colloidal silica such as DuPont Ludox° AM, average particle diameter 0.012 pm; and poly(methyl methacrylate) beads, average particle diameter 0.5 um. In a preferred embodiment, carbon black is employed.
• the particle size of the particulate material employed in the invention can vary widely, as evidenced by the range of particle sizes shown above. In general, the particle size will range from 0.01 um to 0.5 um.
• the amount of particulate material to be coated can also vary widely, as long as the volume percentage of particulate material in the hydrophilic material-particulate material mixture in that layer is from 5 to 75 percent. Where less than 5 percent, or more than 75 percent, of particulate material is employed the desirable improvements in layer separation will not be realized. This percentage is commonly referred to in the art as a PVC percentage (pigment volume content). A preferred range of PVC percentages for the invention is from 10 to 50 percent.
• the amount of particulate material to be coated in the hydrophilic layer is a function of its density.
• Particulate material has been employed in photographic elements for a number of reasons.
• U.S. Patent 4,259,5108 discussed above, it is disclosed in column 4 that silica particles in the outermost layer prevents blocking when the stripping layer is wound upon itself.
• Such materials are known in the art as "anti-blocking" agents. It would have been expected, therefore, that such material in a layer would decrease the adhesion of that layer to an adjacent layer. It was unexpectedly found in accordance with this invention, however, that just the opposite occurred. It was found that the hydrophilic layer adjacent the stripping layer which contains the particulate material has a stronger bond to the stripping layer than does the hydrophilic layer on the other side thereof.
• the stripped image-receiving layer in that case will have a clean appearance on the reverse side thereof.
• particulate material in one of the hydrophilic layers adjacent to the stripping layer in the assemblages described herein is the means whereby the bond between these two layers can be strengthened. This ensures that stripping will take place at the opposite side of the stripping layer.
• the hydrophilic layer on the opposite side of the stripping layer should be substantially free of particulate material since any appreciable amount of particulate material in that layer would tend undesirably to strengthen the bond between that layer and the stripping layer.
• This invention can be used in diffusion transfer assemblages where a reflection print is obtained without the bulkiness of silver halide and other layers, the spent pod and trap.
• the assemblages of this invention combines the handling and storage characteristics of conventional photographs with the convenience and benefits of instant photography. Transparencies can also be obtained in the same manner.
• transparency elements can also be obtained in accordance with the invention by employing a transparent support and utilizing the retained image in the element along with the subsequent removal of residual image dye, silver halide and opacifying layers.
• the particulate material would be located in the hydrophilic layer between the stripping layer and the dye image-receiving layer. Clean separation would then occur on the other side of the stripping layer where it is desired.
• a process for producing a photographic image in color according to this invention comprises:
• the photographic element in the above- described process can be treated with an alkaline processing composition to effect or initiate development in any manner.
• a preferred method for applying processing composition is by use of a rupturable container or pod,which contains the composition.
• the means containing the alkaline processing composition is a rupturable container or pod which is adapted to be positioned during processing of the assemblage so that a compressive force applied to the container by pressure-applying members, such as would be found in a camera designed for in-camera processing, will effect a discharge of the container's contents within the assemblage.
• the dye image-providing material useful in this invention is either positive- or negative-working, and is either initially mobile or immobile in the photographic element during processing with an alkaline composition.
• a format for integral negative-receiver photographic elements in which the present invention is useful is disclosed in Canadian Patent 928,559.
• the support for the photographic element is transparent and is coated with the image-receiving layer, a substantially opaque, light- reflective layer, the stripping layer and adjacent hydrophilic layers described above, and the photosensitive layer or layers described above.
• a rupturable container, containing an alkaline processing composition including a developing agent and an opacifier, is positioned between the top layer and a transparent cover sheet which has thereon, in sequence, a neutralizing layer, and a timing layer.
• the film unit is placed in a camera, exposed through the transparent cover sheet and then passed through a pair of pressure-applying members in the camera as it is being removed therefrom.
• the pressure-applying members rupture the container and spread processing composition and opacifier over the negative portion of the film unit to render it light-insensitive.
• the processing composition develops each silver halide layer and dye images, formed as a result of development, diffuse to the image-receiving layer to provide a positive, right-reading image which is viewed through the transparent support on the opaque reflecting layer background.
• each silver halide emulsion layer of the film assembly will have associated therewith a dye image-providing material which possesses a predominant spectral absorption within the region of the visible spectrum to which said silver halide emulsion is sensitive.
• the dye image-providing-material associated with each silver halide emulsion layer is contained either in the silver halide emulsion layer itself or in a layer contiguous to the silver halide emulsion layer.
• a variety of silver halide developing agents are useful in this invention.
• Specific examples of developers or electron transfer agents (ETA's) useful in this invention include hydroquinone, catechol and 3-pyrazolidinone compounds.
• a combination of different ETA's, such as those disclosed in U.S. Patent 3,039,869, can also be employed.
• the neutralizing material will effect a reduction in the pH of the image layer from about 13 or 14 to at least 11 and preferably 5 to 8 within a short time after imbibition. Suitable materials and their functioning are disclosed on pages 22 and 23 of the July 1974 edition of Research Disclosure, and pages 35 through 37 of the July 1975 edition of Research Disclosure.--
• a timing or inert spacer layer can be employed over the neutralizing layer which "times" or controls the pH reduction as a function of the rate at which alkali diffuses through the inert spacer layer. Examples of such timing layers and their functioning are disclosed in the Research Disclosure articles mentioned in the paragraph above concerning neutralizing layers.
• nondiffusing used herein has the meaning commonly applied to the term in photography and denotes materials that for all practical purposes do not migrate or wander through organic colloid layers, such as gelatin, in the photographic elements of the invention in an alkaline medium and preferably when processed in a medium having a pH of 11 or greater. The same meaning is to be attached to the term “immobile”.
• diffusible as applied to the materials of this invention has the converse meaning and denotes materials having the property of diffusing effectively through the colloid layers of the photographic elements in an alkaline medium.
• Mobile has the same meaning as "diffusible”.
• a control integral imaging-receiver (IIR) element was prepared by coating the following layers in the order recited on a transparent poly(ethylene terephthalate) film support. Quantities are parenthetically given in grams per square meter, unless otherwise stated.
• layers 8 and 9 represent the top and bottom layers of a complete IIR such as described in Example 1 of U.S. Patent 4,356,250. For purposes of this test, it was not necessary to have a complete light-sensitive element.
• layer 7 also contained poly(methylmethacrylate) beads (0.56), average particle diameter 0.5 ⁇ m, 47X PVC (pigment volume content).
• layer 7 also contained Cabot Regal 400 carbon black (0.95), average particle diameter 0.07 ⁇ m, PVC 50%.
• a “tape test” was run on the above IIR's. This test has a high correlation with actual stripping performances in actual photographic coatings. The test consists of firmly applying a short strip of 3M Scotch° 810 Magic Transparent Tape on the top of layer 9 of the IIR to be tested and then rapidly pulling on the tape.
• IIR's B through I thus tested stripped at the point between layers 6 and 5, thus indicating the weakest bond in the element.
• control IIR A In control IIR A, a random discontinuous stripping occurred.
• a second tape test was run on the residual element on top of layer 6 to determine the next weakest bond. If layer 6 was not removed by this second test, then the bond between layers 7 and 6 was considered to be strong. If layer 6 was removed by the second tape test, then the bond was considered to be weak (but none-the-less stronger than the bond between layers 6 and 5).
• Layers 8-17 are similar to those described in Example 1 of U.S. Patent 4,356,250 of Irani et al.
• a cover sheet and processing pod were also prepared similar to those in Example 1 of U.S. Patent 4,356,250, and assembled into film assemblages.
• the above film assemblages were exposed to a graduated density color test object (to verify that the stripping layer and adjacent hydrophilic layer had no sensitimetric effect).
• the assemblages were then processed by spreading the contents of the processing pod between the cover sheet and IIR by using a pair of juxtaposed rollers.
• the film assemblages, as assembled, were then incubated for 1 week at room temperature, 3 weeks at room temperature, and 3 weeks at 32°C/15% RH. Each assemblage was then manually peeled apart to separate the receiver portion from the upper silver halide emulsion layers.
• separation should occur between layers 5 and 6 (designated as location 1). Sometimes the separation occurred between layers 6 and 7 (designated as location 2). This leaves objectionably visible irregular shaped areas of the stripping layer on the back of the peeled receiver. In other instances, separation occurred in various locations from layer 8 upward (designated as location 3). This is the least desirable point of separation as the emulsion layer(s) and dye releaser layer(s) are retained on the element with the image and may cause stain problems in addition to being visually objectionable.

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• Engineering & Computer Science (AREA)
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• Physics & Mathematics (AREA)
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• Steroid Compounds (AREA)

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Citations (4)

• 1984
  • 1984-02-02 CA CA000446598A patent/CA1213458A/fr not_active Expired
  • 1984-05-23 EP EP19840303481 patent/EP0127431B1/fr not_active Expired
  • 1984-05-23 JP JP10276184A patent/JPS59220727A/ja active Granted
  • 1984-05-23 DE DE8484303481T patent/DE3474220D1/de not_active Expired

Patent Citations (5)

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