US3615422A - Photographic products and processes - Google Patents

Photographic products and processes Download PDF

Info

Publication number
US3615422A
US3615422A US854491A US3615422DA US3615422A US 3615422 A US3615422 A US 3615422A US 854491 A US854491 A US 854491A US 3615422D A US3615422D A US 3615422DA US 3615422 A US3615422 A US 3615422A
Authority
US
United States
Prior art keywords
dye
silver halide
layer
image
hydratable
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US854491A
Other languages
English (en)
Inventor
Richard J Haberlin
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Polaroid Corp
Original Assignee
Polaroid Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Polaroid Corp filed Critical Polaroid Corp
Application granted granted Critical
Publication of US3615422A publication Critical patent/US3615422A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

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

  • Rothstein ABSTRACT Diffusion transfer photographic products comprising a support carrying at least two selectively sensitized silver halide emulsion layers, each having a dye which is a silver halide developing agent of predetermined color associated therewith, and a layer intermediate the emulsion layers comprising a processing solution permeable and hydratable metal-free synthetic polymer which is permeable to dye image-forming materials substantially only in the hydrated state.
  • the present invention relates to photography and, more particularly, to photographic products particularly adapted for employment in photographic diffusion transfer color processes.
  • the primary objects of the present invention are to provide photographic products, particularly adapted for employment in diffusion transfer photographic color processes; to provide photographic products which include a photosensitive element which comprises a plurality of essential layers including, superposed on a common support, at least two selectively sensitized photosensitive strata each having associated therewith, as color transfer image-forming components, a dye of predetermined color which is a silver halide developing agent, wherein at least two of said sensitized strata and associated dyes are separated from each other by a layer comprising a synthetic, metal-free polymer as specified hereinafter; to provide photographic diffusion transfer products comprising a photosensitive element, of the last-identified type, in combination with a photographic diffusion transfer image-receiving element comprising a plurality of essential layers including a common support carrying a solution dyeable polymeric layer; and to provide photographic diffusion transfer color processes employing photosensitive film units including, in combination, a photosensitive element and a transfer image-receptive element of the last-identified type, and a fluid photographic transfer processing composition.
  • the invention accordingly comprises the product possessing the features, the others and the relation of components and the process involving the several steps and the relation and order of one or more of such steps with respect to each of the others which are exemplified in the following detailed disclosure, and the scope of the application of which will be indicated in the claims.
  • FiGURlE detailed is a diagrammatic enlarged cross-sectional view illustrating the association of element during one stage of the performance of a diffusion transfer process, for the production of a multicolor positive transfer print, the thickness of the various materials being exaggerated.
  • a photosensitive element containing a dye developer that is, a dye which is a silver halide developing agent, and a silver halide emulsion may be exposed and wetted by a liquid processing composition, for example, by immersion, coating, spraying, flowing, etc., in the dark, and the exposed photosensitive element is superposed prior to, during, or after wetting, on a sheetlilte support element which may be utilized as an image-receiving element.
  • the liquid processing composition is applied to the photosensitive element in a substantially uniform layer as the photosensitive element is brought into superposed relationship with the image-receiving layer.
  • the liquid processing composition positioned intermediate the photosensitive element and the image-receiving layer, permeates the emulsion to initiate development of the latent image contained therein.
  • the dye developer is immobilized or precipitated in exposed areas as a consequence of the development of the latent image. This immobilization is apparently, at least in part, due to a change in the solubility characteristics of the dye developer upon oxidation and especially as regards its solubility in alkaline solutions. It may also be due in part to a tanning effect on the emulsion by oxidised developing agent, and in part to a localized exhaustion of alkali as a result of development.
  • the dye developer In unexposed and partially exposed areas of the emulsion, the dye developer is unreacted and diffusible and thus provides an imagewise distribution of unoxidized dye developer dissolved in the liquid processing composition, as a function of the point-to-point degree of exposure of the silver halide emulsion. At least part of this imagewise distribution of unoxidized dye developer is transferred, by imbibition, to a superposed image-receiving layer or element, said transfer substantially excluding oxidized dye developer.
  • the imageqeceiving element receives a depthwise diffusion, from the developed emulsion, of unoxidized dye developer without appreciably disturbing the imagewise distribution thereof to provide the reversed or positive color image of the developed image.
  • the image-receiving element may contain agents adapted to mordant or otherwise fix the diffused, unoxidized dye developer.
  • the desired positive image is revealed by stripping the image-receiving layer from the photosensitive element at the end of a suitable inhibition period.
  • the dye developers are compounds which contain, in the same molecule, both the chromophoric system of a dye and also a silver halide developing function.
  • a silver halide developing function is meant a grouping adapted to develop exposed silver halide.
  • a preferred silver halide development function is a hydroquinonyl group.
  • Other suitable developing functions include ortho-dihydroxyphenyl and orthoand para-amino substituted hydroxyphenyl groups.
  • the development function includes a benzenoid developing function, that is, an aromatic developing group which forms quinonoid or quinone substances when oxidized.
  • Multicolor images may be obtained using color image-form ing components such as, for example, the previously mentioned dye developers, in diffusion transfer processes by several techniques.
  • One such technique contemplates obtaining multicolor transfer images utilizing dye developers by employment of an integral multilayer photosensitive element, such as is disclosed in the aforementioned US. Pat. No. 2,983,606, and particularly with reference to FIG. 9 of the patents drawing, wherein at least two selectively sensitized photosensitive strata, superposed on a single support, are processed, simultaneously and without separation, with a single, common image-receiving layer.
  • a suitable arrangement of this type comprises a support carrying a red-sensitive silver halide stratum, a green-sensitive silver halide emulsion stratum and a blue-sensitive silver halide emulsion stratum, said emulsions having associated therewith, respectively, for example, a cyan dye developer, a magenta dye developer and a yellow dye developer.
  • the dye developer may be utilized in the silver halide emulsion layer, for example, in the form of particles, or it may be employed as a layer behind the appropriate silver halide emulsion strata.
  • Each set of silver halide emulsion and associated dye developer strata are disclosed to be optionally separated from other sets by suitable interlayers, for example, by a layer of gelatin or polyvinyl alcohol.
  • a yellow filter in front of the green-sensitive emulsion and such yellow filter may be incorporated in an interlayer.
  • a yellow dye developer of the appropriate spectral characteristics and present in a state capable of functioning as a yellow filter may be employed.
  • a separate yellow filter may be omitted.
  • the dye developers are dye image-forming materials which are preferably selected for their ability to provide colors that are useful in carrying out subtractive color photography, that is, the previously mentioned cyan, magenta and yellow.
  • the dye developers employed may be incorporated in the respective silver halide emulsion or, in the preferred embodiment in a separate layer behind the respective silver halide emulsion.
  • the dye developer may, for example, be in a coating or layer behind the respective silver halide emulsion and such a layer of dye developer may be applied by use of a coating solution about 0.5 to 8 percent, by weight, of the respective dye developer distributed in a film-forming natural, or
  • nitrocarboxymethyl cellulose as disclosed in U.S. Pat. No. 2,992,104
  • an acylamidobenzene sulfo ester of a partial sulfobenzal of polyvinyl alcohol as disclosed in U.S. Pat. No. 3,043,692
  • polymers of N-alkyl-a,fi-unsaturated carboxamides and copolymers of N-alkyl-a,B-carboxamides with N-hydroxyalkyl-a,B-unsaturated carboxamides as disclosed in U.S. Pat. No.
  • the preparation of the dye developer dispersion may also be obtained by dissolving the dye in an appropriate solvent, or mixture of solvents, and the resultant solution distributed in the polymeric binder, with optional subsequent removal of the solvent, or solvents, employed, as, for example, by vaporization where the selected solvent, or solvents, possesses a sufficiently low boiling point or washing where the selected solvent, or solvents, possesses a sufficiently high differential solubility in the wash medium, for example, water, when measured against the solubility of the remaining composition components, and/or obtained by dissolving both the polymeric binder and dye in a common solvent.
  • U.S. Pat. No. 3,362,819 discloses image-receiving elements, particularly. adapted for employment in the preceding diffusion transfer processes, which comprise a support layer possessing on one surface thereof, in sequence, a polymeric acid layer, preferably an inert timing or spacer layer, and an imagereceiving layer adapted to provide a visible image upon transfer to said layer of diffusible dye image-forming substance.
  • the polymeric acid layer comprises polymers which contain acid groups, such as carboxylic acid and sulfonic acid groups, which are capable of forming salts with alkali metals, such as sodium potassium, etc., or with organic bases, particularly quaternary ammonium bases, such as tetramethyl ammonium hydroxide, or potentially acid-yielding groups, such as anhydrides or lactones, or other groups which are capable of reacting with bases to capture and retain them.
  • the acid-reacting group is, of course, nondiffusible from the acid polymer layer.
  • the acid polymer contains free carboxy groups and the transfer processing composition employed contains a large concentration of sodium and/or potassium ions.
  • the acid polymers stated to be most useful are characterized by containing free carboxyl groups, being insoluble in water in the free acid form, and by forming watersoluble sodium and/or potassium salts.
  • dibasic acid halfester derivatives of cellulose modified with sulfoanhydrides e.g., with ortho-sulfobenzoic anhydride
  • polystyrene sulfonic acid carboxymethyl cellulose
  • polyvinyl hydrogen phthalate polyvinyl acetate hydrogen phthalate
  • polyacrylic acid acetals of polyvinyl alcohol with carboxy or sulfo-substituted aldehydes, e.g., o-, m-, or p-benzaldehyde sulfonic acid or carboxylic acid
  • partial esters of ethylene/maleic anhydride copolymers partial esters of methyl-vinyl ether/maleic anhydride copolymers
  • the acid polymer layer is disclosed to contain at least sufficient-acid groups to effect a reduction in the pH of the image layer from a pH of about 13 to 14 to a pH of at least 11 or lower at the end of the imbibition period, and preferably to a pH of about 5 to 8 within a short time after imbibition.
  • the pH of the processing composition preferably is of the order of at least 13 to 14.
  • the action of the polymeric acid be so controlled as not to interfere with either development of the negative or image transfer of unoxidized dye developers.
  • the pH of the image layer is kept at a level of pH 12 to 14 until the positive dye image has been formed, after which the pH is reduced very rapidly to at least about pH 1 1, and preferably about pH 9 to 10, which renders unoxidized dye developer substantially nondiffusible.
  • Unoxidized dye developers containing hydroquinonyl developing radicals diffuse from the negative to the positive as the sodium or other alkali salt.
  • the diffusion rate of such dye image-forming components thus is at least partly a function of the alkali concentration, and it is necessary that the pH of the image layer remain on the order of 12 to 14 until transfer of the necessary quantity of dye has been accomplished.
  • the subsequent pl-l reduction in addition to its desirable effect upon image light stability, serves a highly valuable photographic function by substantially terminating further dye transfer.
  • the acid groups are disclosed to be so distributed in the acid polymer layer that the rate of their availability to the alkali is controllable, e.g., as a function of the rate of swelling of the polymer layer which rate in turn has a direct relationship to the diffusion rate of the alkali ions.
  • the desired distribution of the acid groups in the acid polymer layer may be effected by mixing the acid polymer with a polymer free of acid groups, or lower in concentration of acid groups, and compatible therewith, or by using only the acid polymer but selecting one having a relatively lower proportion of acid groups.
  • the layer containing the polymeric acid may contain a water insoluble polymer, preferably a cellulose ester, which acts to control or modulate the rate at which the alkali salt of the polymer acid is formed.
  • a water insoluble polymer preferably a cellulose ester
  • cellulose esters contemplated for use mention is made of cellulose acetate, cellulose acetate butyrate, etc.
  • the particular polymers and combinations of polymers employed in any given embodiment are, of course, selected so as to have adequate wet and dry strength and when necessary or desirable, suitable subcoats may be employed to help the various polymeric layers adhere to each other during storage and use.
  • the inert spacer layer of the aforementioned patent acts to time" control the pH reduction by the polymeric acid layer. This timing is disclosed to be a function of the rate at which the alkali diffuses through the inert spacer layer. It was stated to have been found that the pH does not drop until the alkali has passed through the spacer layer, i.e., the pH is not reduced to any significant extent by the mere diffusion into the interlayer, but the pH drops quite rapidly once the alkali diffuses through the spacer layer.
  • Other such spacer layers which are suitable for use in the image-receiving element are disclosed and claimed in U.S. Pat. No. 3,421 ,893.
  • solution dyeable polymers such as nylons as, for example, N-methoxymethyl polyhexamethylene adipamide; partially hydrolyzed polyvinyl acetate; polyvinyl alcohol with or without plasticizers; cellulose acetate with fillers as, for example, one-half cellulose acetate and one-half oleic acid; gelatin; and other materials of a similar nature.
  • Preferred materials comprise polyvinyl alcohol or gelatin containing a dye mordant such as poly-4-vinylpyridine, as disclosed in U.S. Pat. No. 3,148,061.
  • the liquid processing composition referred to for effecting multicolor diffusion transfer processes comprises at least an aqueous solution of an alkaline material, for example, diethylamine, sodium hydroxide or sodium carbonate and the like, and preferably possessing a pH in excess of 12, and most preferably, a viscosity-increasing compound constituting a film-forming material of the type which, when the composition is spread and dried, forms a relatively firm and relatively stable film.
  • the preferred film'forming materials disclosed comprise high molecular weight polymers such as polymeric, water-soluble ethers which are inert to an alkaline solution such as, for example, a hydroxyethyl cellulose or sodium carboxymethyl cellulose.
  • film-forming materials or thickening agents whose ability to increase viscosity is substantially unaffected if left in solution for along period of time are also disclosed to be capable of utilization.
  • the film-forming material is preferably contained in the processing composition in such suitable quantities as to impart to the composition a viscosity in excess of 100 c.p.s. at a temperature of approximately 24 C. and preferably in the order of 100,000 c.p.s. to 200,000 c.p.s. at that temperature.
  • the silver halide crystals may be prepared by reacting a water-soluble silver salt, such as silver nitrate, with at least one water-soluble halide, such as ammonium, potassium or sodium bromide, preferably together with a corresponding iodide, in an aqueous solution of a peptizing agent such as a colloidal gelatin solution; digesting the dispersion at an elevated temperature, to provide increased crystal growth; washing the resultant dispersion to remove undesirable reaction products and residual water-soluble salts by chilling the dispersion, noodling the set dispersion, and washing the noodles with cold water, or, alternatively, employing any of the various flocc systems, or procedures, adapted to effect removal of undesired components, for example, the procedures described in U.S. Pat. Nos. 2,614,928; 2,614,929; 2,728,662; and the like; afterripening the dis
  • Optical sensitization of the emulsion's silver halide crystals may be accomplished by contact of the emulsion composition with an effective concentration of the selected optical sensitizing dyes dissolved in an appropriate dispersing solvent such as methanol, ethanol, acetone, water, and the like; all according to the traditional procedures of the art, as described in Hammer, 1F. ML, The Cyanine Dyes and Related Compounds.
  • an appropriate dispersing solvent such as methanol, ethanol, acetone, water, and the like
  • Additional optional additives such as coating aids, hardeners, viscosity-increasing agents, stabilizers, preservatives, and the like, for example, those set forth hereinafter, also may be incorporated in the emulsion formulation, accord ing to the conventional procedures known in the photographic emulsion manufacturing art.
  • the photoresponsive material of the photographic emulsion will, as previously described, preferably comprise a crystal of silver, for example, one or more of the silver halides such as silver chloride, silver iodide, silver bromide, or mixed silver halides such as silver chlorobromide or silver iodobromide, of varying halide ratios and varying silver concentrations.
  • the silver halides such as silver chloride, silver iodide, silver bromide, or mixed silver halides such as silver chlorobromide or silver iodobromide, of varying halide ratios and varying silver concentrations.
  • the emulsions may include the various adjuncts, or addenda, according to the techniques disclosed in the art.
  • the aforementioned gelatin may be, in whole or in part, replaced with some other colloidal material such as albumin; casein; or zein; or resins such as a cellulose derivative, as described in U.S. Pat. Nos. 2,322,085 and 2,327,808; polyacrylamides, as described in U.S. Pat. No. 2,541,474; vinyl polymers such as described in a multiplicity of readily available U.S. Patents.
  • an image-receiving elements need not be separated from superposed contact with a photosensitive element comprising a silver halide emulsion subsequent to substantial transfer image formation if the image-receiving element is transparent and a processing composition containing a substance rendering the processing composition layer opaque is spread between the image-receiving layer and the photosensitive element.
  • a processing composition containing a substance rendering the processing composition layer opaque is spread between the image-receiving layer and the photosensitive element.
  • an integral diffusion transfer photographic film unit particularly adapted for the production of a dye transfer image of improved stability will be constructed, for example, in accordance with aforementioned U.S. Pat. No. 3,415,644 to include a photosensitive element comprising a laminate having in sequence as essential layers, a dimensionally stable opaque support layer, a photosensitive silver halide emulsion layer having associated therewith dye image-providing material which is soluble and diffusible in alkali at a first pfi, an alkaline solution permeable polymeric layer dyeable by the dye image-providing material, a polymeric acid layer containing sufficient acidifying material to effect reduction subsequent to substantial transfer dye image formation of a processing solution having the first pH to a second pH at which said dye image-providing material is insoluble and nondiffusible, and a dimensionally stable transparent support layer, said dimensionally stable support layers comprising extremities of the described photographic film unit composite structure.
  • a rupturable container retaining an aqueous alkaline processing composition having the first pH and containing an opacifying agent in a quantity sufficient to mask the dye image-providing material, is fixedly positioned and extends transverse the leading edge of the laminate whereby to effect unidirectional discharge of the containers contents between the alkaline solution permeable and dyeable polymeric layer and the photosensitive silver halide emulsion layer next adjacent thereto upon application of compressive force to the container.
  • photographic elements having at least two adjacent dye image-forming units each of which comprise silver halide emulsion and dye developer contiguous to the silver halide emulsion may be separated by an alkali-permeable water-insoluble stratum of a polyvalent metal salt of a film-forming alkali-permeable water-soluble polymer having free carboxylic acid groups, the stratum being less permeable to dye developer in aqueous alkaline solution than the polymeric carboxylic acid used to prepare the salt stratum.
  • the barrier effect provided by the salt stratum operates on a cross-link mechanism, i.e., polyvalent metal moieties are used to form the requisite salts by cross-linking carboxylic acid moieties of the polymeric carboxylic acid to form a stratum having a certain degree of alkali permeability and water insolubility which serves as a barrier to prevent color contamination and interdevelopment between dye image-forming units.
  • a cross-link mechanism i.e., polyvalent metal moieties are used to form the requisite salts by cross-linking carboxylic acid moieties of the polymeric carboxylic acid to form a stratum having a certain degree of alkali permeability and water insolubility which serves as a barrier to prevent color contamination and interdevelopment between dye image-forming units.
  • the cross-link configurations would be, for example,
  • the interlayer of the present invention is metal-free, that is, it does not depend upon metal complexing of polymeric constituents to provide the desired effect; is preferably substantially uncross-linked, that is, there is no reliance on cross-linking to provide the functionality of the present invention; and is preferably waterinsoluble. It will be patently evident, therefore, that the polymeric interlayer of the present invention which is metalfree, preferably substantially uncross-linked and water-insoluble provides a diffusion control mechanism both functionally and structurally dissimilar from that described in U.S. Pat. No. 3,384,483.
  • one or more of the interlayers of the integral multilayer photosensitive element is specifically selected to comprise a processing composition permeable and hydratable metal-free synthetic polymer having a dye-permeable lattice, that is, which is permeable to dye image-forming materials substantially only in the hydrated state, and a hydration rate less than the development and greater than the fogging rates of the dye associated silver halide next adjacent the photosensitive element's film base, significant improvement may be achieved with respect to the element's color isolation and potential photographic process speed, and with respect to the brilliance, density and hue of the transfer image color characteristics. in addition to being metal-free, the denoted polymer will preferably be substantially uncross-linked.
  • employment of the detailed polymeric interlayer acts to provide a barrier with respect to retardation of the positional displacement of the dye prior to establishment of substantial imagewise emulsion control of the associated dyes diffusion, with the concomitant results of providing significantly higher process speed, higher transfer image maximum densities, greater cyan and magenta dye saturation, and improved red and blue hues, in addition to, and by reason of, improved photosensitive element interimage effects.
  • These effects result, at least in part, from prevention of the respective dyes development of silver halide emulsion strata, other than the specific strata with which the individual dye is directly associated; generally characterized, respectively, as yellow, magenta, and cyan drop-off".
  • the hydration with which the present system is directly concerned comprises, in general, the polymer's assimilation of water molecules by hydrogen bonding with its correlated concomitant swelling. It will also be recognized that in a given instance, the hydration and permeation of a selected specific polymer, within the photographic system context detailed, will be influenced and modulated by the polymer's relative hydrolysis, salt formation, solubility, and the like, properties.
  • the hydratable metal-free synthetic polymers disclosed possess the intrinsic capability to combine with water to provide a stratum which is, in its hydrated or combined state, permeable to material to which it is impermeable in its anhydrous condition.
  • the polymeric barrier material disclosed is permeable to alkali so that development of the photographic system may be initiated immediately, but due to the relatively large size of dye molecules, image-forming dye may not penetrate the barrier until it has achieved a hydrated condition.
  • Image-forming dye associated with the silver halide emulsions of the present invention is held immobile by the disclosed barrier material until the silver halide emulsion having the slowest development rate is substantially developed.
  • diffusion through said barrier material is not held up so long that the silver halide emulsion having the fastest development rate will fog thereby preventing image-forming dye from reaching the image-receiving element.
  • parameters for hydration and/or development of adjacent silver halide emulsions may be determined using conventional techniques.
  • the paramount consideration is balancing the relativity of the hydration rate of the barrier material to the development and fogging rates of the related silver halide emulsions.
  • Absolute numbers may only be used to describe one given system. Broadly speaking one of ordinary skill in the art possessing the present invention would be able to determine the specific parameters which must be utilized in designing the barrier material of the present invention when the fogging and development rates of the associated silver halide emulsions are known.
  • the respective rates of silver halide emulsion development, polymer hydration, and/or silver halide emulsion fogging may be directly measured, in accordance with any of the conventional techniques known in the art. Included among such techniques are procedures well known for the simultaneous derivation of both the development and fogging rate of a silver halide emulsion, by contemporaneous measurement of silver developed, per unit time, in exposed and unexposed portions of an emulsion stratum.
  • a particularly apt and simple empirical method of initially determining the effective ness of a selected hydratable polymer within the context of its ultimate photographic employment, has been found to comprise the rapid and simple procedure of microtoming a micron cross section of the integral multilayer structure, mounting same on a microscope slide which had previously been coated with a thin layer of a microscope objective immersion oil, covering the microtome section with a cover slip and including alkali solution, to the contact edge of the section, by capillary action.
  • the effective barrier propensity of the selected polymer may then be visually recorded and corre' lated timewise with respect to development of the photosensitive emulsion strata.
  • the fogging rate of the silver halide emulsions employed may be suitably modulated by incorporation of a conventional antifoggant, such as those hereinbefore detailed, in the emulsion layer itself and/or associated layers and/or processing composition, and permeation of such agent, or agents, into the respective emulsion layer to be controlled.
  • a conventional antifoggant such as those hereinbefore detailed
  • the gelatino silver halide emulsion layers are about 0.6 to 6 microns thick, the gelatino dye-retaining layers are about 1 to 7 microns thick, and the polymer interlayers are l to 5 microns thick.
  • the image-receiving layer is about 0.25 to 0.4 mil. thick, the polymeric acid layer is about 0.3 to 1.5 mils. thick, and the spacer layer is about 0.1 to 0.7 mil. thick.
  • the instant invention is thus directly concerned with a photosensitive element which comprises a common support having, positioned on one surface, at least two selectively sensitized photosensitive silver halide emulsion strata, for example, having predominant spectral sensitivity to separate regions of the spectrum, each having a dye of predetermined color associated therewith, for example, a spectral absorption range substantially complimentary to the predominant sensitivity range of the associated emulsion, subsequent to processing, separated by a spacer or interlayer comprising the aforementioned hydratable polymer alone or in combination with one or more additional polymers, such as gelatin, polyvinyl alcohol, and the like, and retaining photographic processing adjuncts where desired.
  • a photosensitive element which comprises a common support having, positioned on one surface, at least two selectively sensitized photosensitive silver halide emulsion strata, for example, having predominant spectral sensitivity to separate regions of the spectrum, each having a dye of predetermined color associated therewith, for example, a spectral absorption range substantially complimentary to the predominant
  • the selected polymer is aqueous alkaline solution permeable and hydratable; most preferably, substantially instantaneously permeable by solution retained molecules having a geometric size less than the geometric size of the transfer image-forming dye, such as, for example, auxiliary silver halide developing agents, antifoggants, accelerators, arrestors, and the like, in order that photographic development, and the like, may proceed, with respect to the emulsion next adjacent the film base, within the earliest time sequence possible.
  • the transfer image-forming dye such as, for example, auxiliary silver halide developing agents, antifoggants, accelerators, arrestors, and the like, in order that photographic development, and the like, may proceed, with respect to the emulsion next adjacent the film base, within the earliest time sequence possible.
  • the selected hydratable polymer possesses a processing composition hydration rate sufficiently less than the development rate and greater than the fogging rate of the respective dye associated silver halide emulsion possessing the slowest development rate and the most rapid fogging rate of the two emulsions intermediate which the polymer is positioned; in order to simultaneously retard rearward diffusion of the dye associated with the silver halide emulsion next adjacent the elements surface and forward diffusion of the dye associated with the silver halide emulsion nert adjacent the film base, until the respective imagewise emulsion development and control of each dye is substantially established.
  • aqueous alkaline solution hydratable polymers particularly adapted for employment in accordance with the instant invention, mention maybe made of:
  • materials suitable for utilization within the environment of the present invention comprise those disclosed in US. Pat. No. 3,421,892 and include poly-N-methacrylamide; poly- N-methylmethacrylamide; poly-N'ethylacrylamide; ter polymers of N-ethylacrylamide, N-methyl-acrylamide, and acrylamide; copolymers of N-ethylacrylamide and 2-vinylpyridine; copolymers of N-isopropylacrylamide and dimethylaminoethylacrylate; copolymers of N- isopropylacrylamide and N-vinylpyrolidone; etc.
  • the synthetic metal-free polymeric material utilized to provide barrier functionality will comprise a substantially uncross-linked water-insoluble material.
  • water-insoluble materials provide an added feature in that they may be utilized in thicknesses somewhat less than similar barriers laid down of materials which are inherently water-soluble.
  • the present invention has been specifically found to possess certain distinct advantages, when compared with certain interlayer systems of the prior art, in order to effect processing in a stepwise, or layerwise, manner.
  • the prior art teaches the employment of a barrier interlayer to separate an outer emulsion layer and associated dye from an inner emulsion layer and its associated dye, in order that processing may be effected in the stepwise manner.
  • the barrier layer comprises, in general, a polymeric layer which is permeated by the fluid processing composition at a rate sufficiently slow so as to insure that permeation of the fluid composition, from an outer emulsion layer into the next inner emulsion layer, is deferred, until processing of the outer emulsion layer is substantially complete.
  • barrier interlayers of this type comprise two distinct types.
  • the first type comprises impermeable polymeric interlayers which possess a solution rate, upon contact with the fluid processing composition, during photographic processing, such that the interlayer requires a longer time span to be rendered permeable than the time interval necessitated to effect development of the outer emulsion stratum.
  • the second type comprises impermeable polymeric interlayers which possess a hydrolysis rate, upon contact with the fluid processing composition, such that the interlayer requires a time interval for the occurrence of hydrolysis, suffrcient as to provide processing composition permeability, in excess of that required to effect development of the outer emulsion.
  • the present invention possesses, when compared with such prior art systems, the specific advantage of providing the previously stated control of dye diflu sion during substantially contemporaneous development of all the emulsion strata constituting the integral multilayer photosensitive element.
  • the positioning of the respective silver halide emulsion/dye developer units of the tripack configuration detailed above may be varied.
  • a selectively exposed photosensitive element 25 comprises: a support a layer 11 containing a cyan dye developer; a layer 12 comprising a redsensitive silver halide emulsion; an interlayer 13 comprising the polymer detailed above; a layer 14 containing a magenta dye developer; a layer 15 comprising a green-sensitive silver halide emulsion; an interlayer 16 comprising the polymer detailed above; a layer 17 containing a yellow dye developer; a layer 18 comprising a blue-sensitive silver halide emulsion; and a protective overcoat layer 19.
  • the multilayer exposed photosensitive element 25 is shown in processing relationship with an image-receiving element 26 which, as aforenoted, may be permanently integral therewith, and a layer 20 of processing composition distributed intermediate elements and 26.
  • Image-receiving element 26 comprises: a support 24 which may be transparent; a neutralizing layer 23; a spacer layer 22; and an image-receiving layer 21.
  • liquid processing composition 20 is effective to initiate development of the latent images in the respective silver halide emulsion strata and hydration of the polymeric interlayers. After a suitable imbibition period, during which at least a portion of the dye developer associated with unexposed areas of each of the emulsions is transferred to superposed image-receiving element 26, the latter element may be separated to reveal the positive multicolor image.
  • a photosensitive element similar to that shown in the drawing was prepared by coating, in succession, on a gelatin subbed cellulose triacetate film base, the following layers;
  • a layer of the cyan dye developer 1,4-bis-(B-[hydroquinoyl-a-methyl1-ethylamino)-5,8-dihydroxy-anthraquinone dissolved in diethyl lauramide, dispersed in gelatin and coated at a coverage of 159 mgs. per square foot of dye and 119 mgs. per square foot of gelatin.
  • Additional photosensitive elements substantially of the lastidentified type also were fabricated employing, as Layer 3, a mixture comprising mgs. per square foot and 10 mgs. per square foot; 1 ll mgs. per square foot and 14 mgs. per square foot; 134 mgs. per square foot and l6 mgs. per square foot; and 156 mgs. per square foot and 19 mgs. per square foot, of the identified crotonic acid copolymer and gelatin, respectively.
  • a photosensitive element substantially of the last-identified type was also fabricated employing, as Layer 3, 180 mgs. per square foot of gelatin and 10 mgs. per square foot of 4-methyl-phenyl hydroquinone, the latter shifted from Layer 2.
  • the coverages of Layers 4 and 7 were increased by 10 percent.
  • the required number of image-receiving elements were prepared by coating a cellulose nitrate subcoated baryta paper with the partial butyl ester of polyethylene/maleic anhydride copolymer prepared by refluxing, for 14 hours, 300 grams of high viscosity poly-(ethylene/maleic anhydride), grams of n-butyl alcohol and 1 cc. of 85 percent phosphoric acid to provide a polymeric acid layer approximately 0.75 mils. thick.
  • the external surface of the spacer layer was then coated with a 2:1 mixture, by weight, of polyvinyl alcohol and poly-4- vinylpyridine, at a coverage of approximately 600 mgs. per square foot, to provide a polymeric image-receiving layer approximately 0.40 mils. thick.
  • the thus-prepared image-receiving element was then baked at F. for 30 minutes and then allowed to cool.
  • aqueous liquid processing composition comprising:
  • Potassium hydroxide l 1.2 g. Hydroxyethyl cellulose (high viscosity) [commercially available from Hercules Powder Co., Wilmington 99, Del., under the trade name Natrasol 250) 3.9 g. Potassium thiosulfate 0.5 g. Benzotriazole 3.5 g. N-benzyl-a-picolinium bromide 2.0 g. Lithium Hydroxide 0.5 g.
  • Photographic and visual examination of exposed and processed photosensitive element microtome sections revealed decreased interimage effects within the processed element fabricated in accordance with the instant invention, as compared with the control element; especially noted was a substantial decrease in amount of magenta drop off.”
  • the identified hydroxypropyl cellulose, methyl acrylate-acrylic acid, acrylonitrile-acrylic acid, and hydroxypropyl methyl cellulose provided results substantially identical with those detailed with respect to the employment of the designated vinyl acetatecrotonic acid copolymer.
  • polyvinyl hydrogen phthalate and polyacrylic acid provided a hydration rate more rapid than the development rate of the respective silver halide emulsion strata next adjacent the support and, as a result, failed to provide the advantageous results detailed above.
  • the dye densities reported herein are differential dye densities, i.e., maximum dye densities minus stain (D,,,,,,,.D,,,,,,).
  • liquid processing composition employed may contain an auxiliary or accelerating developing agent, such as p-methylaminophenol, 2,4-diamino-phenol, pbenzylaminophenol, hydroquinone, toluhydroquinine, phenylhydroquinone, 4'-methylphenylhydroquinone, etc. It is also contemplated to employ a plurality of auxiliary or accelerating developing agents, such as 3-pyrazolidone developing agent and a benzenoid developing agent, as disclosed in U.S. Pat. No. 3,039,869, issued June 19, 1962.
  • auxiliary developing agents examples include l-phenyl-ii-pyrazolidone in combination with pbenzylaminophenol and l-phenyl-3-pyrazolidone in combination with 2,5-bis-ethyleneimino hydroquinone.
  • auxiliary lid developing agents may be employed in the liquid processing composition or they may be initially incorporated, at least in part, in any one or more of the silver halide emulsion strata, the strata containing the dye developers, the interlayers, the overcoat layer, the image-receiving layer, or in any other auxiliary layer, or layers, of the film unit.
  • the dye developer oxidized during development may be oxidized and immobilized as a result of a reaction, e.g., an energy-transfer reaction, with the oxidation product of an oxidized auxiliary developing agent, the latter developing agent being oxidized by the development of exposed silver halide.
  • a reaction e.g., an energy-transfer reaction
  • Such a reaction of oxidized developing agent with unoxidized dye developer would regenerate the auxiliary developing agent for further reaction with the exposed silver halide.
  • development may be effected in the presence of an onium compound, particularly a quaternary ammonium compound, in accordance with the process disclosed in U.S. Pat. No. 3,173,786.
  • color diffusion transfer processes which employ color coupling techniques comprising, at least in part, reacting one or more color developing agents and one or more color formers or couplers to provide a dye transfer image to a superposed image-receiving layer and those disclosed in U.S. Pat. No. 2,774,668, issued Dec. 18, 1956, wherein color diffusion transfer processes are described which employ the imagewise differential transfer or complete dyes by the mechanisms therein described to provide a transfer dye image to a contiguous image-receiving layer.
  • a camera apparatus suitable for processing film of the type just mentioned is provided by the Polaroid Land Camera, sold by Polaroid Corporation, Cambridge, Mass, or similar camera structure such, for example, as the roll film type camera forming the subject matter of U.S. Pat. No. 2,435,717 or the film pack type camera forming the subject matter of U.S. Pat. No. 2,991,702.
  • Camera apparatus of this type permits successive exposure of individual frames of the photosensitive element from the emulsion side thereof as well as individual processing of an exposed frame by bringing said exposed frame into superposed relation with a predetermined portion of the image-receiving element while drawing those portions of the film assembly between a pair of pressure rollers which require a container associated therewith and effect the spreading of the processing liquid released by rupture of said container, between and in contact with exposed photosensitive frame and the predetermined, registered area of the image-receiving element.
  • the relative proportions of the agents of the diffusion transfer processing composition may be altered to suit the requirements of the operator.
  • "to modify the herein described developing compositions by the substitution of preservatives, allralies, silver halide solvents, etc., other than those specifically mentioned, provided that the pH of the composition is preferably in excess of at least 10 initially.
  • the concentration of various components may be varied over a wide range and when desirable adaptable components may be disposed in the photosensitive element, prior to exposure, in a separate permeable layer of the photosensitive element and/or in the photosensitive emulsion.
  • the support layers referred to may comprise any of the various types of conventional rigid or flexible supports, for example, glass, paper, metal, and polymeric films of both synthetic types and those derived from naturally occurring products.
  • Suitable materials include paper; aluminum; polymethacrylic acid methyl and ethyl esters; vinyl chloride polymers; polyvinyl acetal; polyamides such as nylon; polyesters such as polymeric films derived from ethylene glycol terephthalic acid; and cellulose derivatives such as cellulose acetate, triacetate, nitrate, propionate, butyrate, acetatepropionate, or acetate-butyrate.
  • a rupturable container provides a convenient means for spreading a liquid processing composition between layers of film unit whereby to permit the processing to be carried out within a camera apparatus
  • the practices of this invention may be otherwise effected.
  • a photosensitive element after exposure in suitable apparatus and while preventing further exposure thereafter to actinic light, may be removed from such apparatus and permeated with the liquid processing composition, as by coating the composition on said photosensitive element or otherwise wetting said element with the composition, following which the permeated, exposed photosensitive element, still, without additional exposure to actinic light, is brought into contact with the image-receiving element for image formation in the manner heretofore described.
  • expression positive image is intended to cover such an image produced on the image-carrying layer.
  • the film unit structure may also comprise an integral positive/negative construction carried on a single support.
  • the polymeric interlayer preferably has a measured thickness not less than 20 percent and not exceeding twice the thickness and coverage of the silver halide emulsion stratum next adjacent the support.
  • the film unit may also contain one or more subcoats or layers, which, in turn, may contain one or more additives such as plasticizers, intermediate essential layers for the purpose, for example, of improving adhesion.
  • additives such as plasticizers, intermediate essential layers for the purpose, for example, of improving adhesion.
  • a photosensitive element which comprises, in combination:
  • said hydratable synthetic polymer is selected from the group consisting of cellulosic and vinyl polymers.
  • said hydratable synthetic polymer comprises a vinyl acetate-crotonic acid copolymer having less than 5 percent crotonic acid by weight.
  • said hydratable synthetic polymer comprises hydroxypropyl cellulose.
  • said hydratable synthetic polymer comprises hydroxypropyl methyl cellulose.
  • a photographic film unit which comprises, in combination:
  • photosensitive element having a diffusion transfer imagereceiving element affixed at least one edge thereof, said photosensitive element comprising as essential layers:
  • a support layer d. a support layer; and I e. an alkaline processing composition permeable and dyeable polymeric layer; wherein said photosensitive and said image-receiving elements are adapted to be superposed, the support layers of each comprising the extremities of the superposed structure.
  • said image receiving element additionally comprises a polymeric acid layer intermediate the support layer and dyeable polymeric layer.
  • the invention of claim 10 including a rupturable container retaining an aqueous alkaline processing solution affixed one edge of said photosensitive and said image-receiving elements and adapted upon rupture to distribute the contents intermediate said photosensitive element and said imagereceiving element.
  • said photographic film unit comprises a composite structure comprising said photosensitive element and said image-receiving element permanently affixed each to the other in superposed relationship, the support layers of each of said elements comprising the extremities of said composite structure.
  • a photosensitive element containing a plurality of essential layers including in sequence
  • each of said cyan, magenta and yellow dyes being silver halide developing agents and at least one of said spacer layers comprising a processing solution permeable and hydratable metalfree synthetic polymer, which is permeable to dye imageforming materials only in the hydrated state and is processing solution hydratable at a rate which renders said synthetic polymer layer permeable to dye image-forming materials subsequent to substantial development of the dye associated silver halide emulsion possessing the slowest development rate and preceding substantial fogging of the dye associated silver halide emulsion possessing the most rapid fogging rate so that substantial development of said silver halide emulsions is accomplished prior to substantial hydration of said processing solution permeable and hydratable synthetic polymeric spacer layer and resultant diffusion of dye image-forming materials therethrough.
  • hydratable synthetic polymer is selected from the group consisting of cellulosic and vinyl polymers.
  • a process for forming transfer images in color which comprises the steps of:
  • a photosensitive element comprising at least two selectively sensitized silver halide emulsion layers, each having associated therewith a dye image-forming material of predetermined color, said material additionally being a silver halide developing agent, and a layer intermediate at least two of said silver halide emulsion layers comprising an aqueous alkaline processing solution permeable and hydratable metal-free synthetic polymer which is permeable to dye image-forming material only in the hydrated state and is processing solution hydratable at a rate which renders said synthetic polymer layer permeable to dye image-forming materials subsequent to substantial development of the dye associated silver halide emulsion possessing the slowest development rate and preceding substantial fogging of the dye associated silver halide emulsion possessing the most rapid fogging rate so that substantial development of said silver halide emulsions is accomplished prior to substantial hydration of said intermediate layer and resultant diffusion of dye image-forming materials therethrough;
  • hydratable synthetic polymer is selected from the group consisting of vinyl and cellulosic polymers.
  • said synthetic polymer comprises a vinyl acetate-crotonic acid copolymer having less than 5 percent crotonic acid by weight.
  • the invention ofclaim 20 which comprises the steps of: exposing a photosensitive element which comprises bluesensitive, green-sensitive and red-sensitive silver halide emulsion layers mounted on a common support, said blue-sensitive, green-sensitive and red-sensitive silver halide emulsion layers having associated therewith, respectively, yellow, magenta and cyan dyes, each of said dyes being a silver halide developing agent, at least two of said emulsions and associated dyes having interposed therebetween a layer comprising an aqueous alkaline processing solution permeable and hydratable metal-free synthetic polymer which is permeable to dye image-forming material only in the hydrated state and is processing solution hydratable at a rate which renders said synthetic polymer layer permeable to dye image-forming materials subsequent to substantial development of the dye associated silver halide emulsion possessing the slowest development rate and preceding; substantial fogging of the dye associated silver halide emulsion possessing the most rapid fogging rate so that substantial development of said silver halide e
  • synthetic polymer is substantially water-insoluble.

Landscapes

  • Engineering & Computer Science (AREA)
  • Architecture (AREA)
  • Structural Engineering (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Silver Salt Photography Or Processing Solution Therefor (AREA)
  • Heat Sensitive Colour Forming Recording (AREA)
  • Color Printing (AREA)
  • Photosensitive Polymer And Photoresist Processing (AREA)
US854491A 1965-04-23 1969-09-02 Photographic products and processes Expired - Lifetime US3615422A (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
US45030565A 1965-04-23 1965-04-23
US48686265A 1965-09-13 1965-09-13
US85449169A 1969-09-02 1969-09-02

Publications (1)

Publication Number Publication Date
US3615422A true US3615422A (en) 1971-10-26

Family

ID=27412445

Family Applications (1)

Application Number Title Priority Date Filing Date
US854491A Expired - Lifetime US3615422A (en) 1965-04-23 1969-09-02 Photographic products and processes

Country Status (6)

Country Link
US (1) US3615422A (enrdf_load_stackoverflow)
BE (1) BE679642A (enrdf_load_stackoverflow)
DE (1) DE1547991C3 (enrdf_load_stackoverflow)
GB (1) GB1125922A (enrdf_load_stackoverflow)
MY (1) MY6900323A (enrdf_load_stackoverflow)
NL (1) NL149916B (enrdf_load_stackoverflow)

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3856522A (en) * 1972-12-26 1974-12-24 Polaroid Corp Spacer layer for dye diffusion transfer film
US4056394A (en) * 1976-04-14 1977-11-01 Eastman Kodak Company Timing layer for color transfer film units comprising copolymer with activation energy to penetration greater than 18 kcal/mole
US4061496A (en) * 1976-04-14 1977-12-06 Eastman Kodak Company Combination of two timing layers for photographic products
FR2366599A1 (fr) * 1976-04-14 1978-04-28 Eastman Kodak Co Produit composite pour la photographie en couleurs par diffusion transfert comprenant une couche barriere a activite temporaire
US4088493A (en) * 1974-11-26 1978-05-09 Agfa-Gevaert Aktiengesellschaft Diffusion retarding layers comprising polymers of dimethoxyethylene
US4123275A (en) * 1975-07-24 1978-10-31 Fuji Photo Film Co., Ltd. Color diffusion transfer photographic materials with vinyl copolymer neutralization rate controlling layer
US4148653A (en) * 1976-01-17 1979-04-10 Agfa-Gevaert Ag Restraining layer for retarding the diffusion of hydroxyl ions in the dye diffusion transfer process
US4178182A (en) * 1973-08-24 1979-12-11 Fuji Photo Film Co., Ltd Color diffusion-transfer photographic element
US4288523A (en) * 1980-03-14 1981-09-08 Polaroid Corporation Diffusion control layers in diffusion transfer photographic products
US4297431A (en) * 1978-09-15 1981-10-27 Polaroid Corporation Diffusion control layers in diffusion transfer photographic products
US4426481A (en) 1980-03-14 1984-01-17 Polaroid Corporation Polymeric matrix containing β-eliminating polymer and process for preparing same
US4546159A (en) * 1980-03-14 1985-10-08 Polaroid Corporation Eliminating polymers useful in diffusion control layers

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3856522A (en) * 1972-12-26 1974-12-24 Polaroid Corp Spacer layer for dye diffusion transfer film
US4178182A (en) * 1973-08-24 1979-12-11 Fuji Photo Film Co., Ltd Color diffusion-transfer photographic element
US4088493A (en) * 1974-11-26 1978-05-09 Agfa-Gevaert Aktiengesellschaft Diffusion retarding layers comprising polymers of dimethoxyethylene
US4123275A (en) * 1975-07-24 1978-10-31 Fuji Photo Film Co., Ltd. Color diffusion transfer photographic materials with vinyl copolymer neutralization rate controlling layer
US4148653A (en) * 1976-01-17 1979-04-10 Agfa-Gevaert Ag Restraining layer for retarding the diffusion of hydroxyl ions in the dye diffusion transfer process
US4056394A (en) * 1976-04-14 1977-11-01 Eastman Kodak Company Timing layer for color transfer film units comprising copolymer with activation energy to penetration greater than 18 kcal/mole
US4061496A (en) * 1976-04-14 1977-12-06 Eastman Kodak Company Combination of two timing layers for photographic products
FR2366599A1 (fr) * 1976-04-14 1978-04-28 Eastman Kodak Co Produit composite pour la photographie en couleurs par diffusion transfert comprenant une couche barriere a activite temporaire
US4297431A (en) * 1978-09-15 1981-10-27 Polaroid Corporation Diffusion control layers in diffusion transfer photographic products
US4288523A (en) * 1980-03-14 1981-09-08 Polaroid Corporation Diffusion control layers in diffusion transfer photographic products
US4426481A (en) 1980-03-14 1984-01-17 Polaroid Corporation Polymeric matrix containing β-eliminating polymer and process for preparing same
US4546159A (en) * 1980-03-14 1985-10-08 Polaroid Corporation Eliminating polymers useful in diffusion control layers

Also Published As

Publication number Publication date
GB1125922A (en) 1968-09-05
NL6605430A (enrdf_load_stackoverflow) 1966-10-24
BE679642A (enrdf_load_stackoverflow) 1966-10-18
DE1547991A1 (de) 1970-01-02
MY6900323A (en) 1969-12-31
DE1547991B2 (de) 1979-08-16
DE1547991C3 (de) 1980-05-14
NL149916B (nl) 1976-06-15

Similar Documents

Publication Publication Date Title
US3415644A (en) Novel photographic products and processes
US3594165A (en) Novel photographic products and processes
US3415645A (en) Opaque permeable polymeric layer in photo-sensitive element
US3415646A (en) Novel photographic products and processes
US3615422A (en) Photographic products and processes
US3625685A (en) Photographic color diffusion-transfer element comprising aqueous film-forming synthetic polymer suspension layers intermediate its sensitive layers and processes for their use
US3421892A (en) Novel photographic products and processes
US3473925A (en) Photographic diffusion transfer color process and film unit for use therein
US4009031A (en) Diffusion transfer image-receiving element having polyvinylpyridine layer treated with hydrophilic colloid/ammonia solution
US3748129A (en) Dye image providing materials within diffusion transfer barrier layers
US3619155A (en) Photographic products and processes utilizing a polyvalent metal ion-cross-linked polymeric layer
US3594164A (en) Photographic color diffusion transfer process and film unit for use therein
US3579333A (en) Multicolor diffusion transfer photographic products and processes with a developing composition comprising a desensitizing agent
US3615543A (en) Multicolor photographic element comprising an oxacyanine sensitizing dye
US3734727A (en) Photographic products and processes
US3772026A (en) Colorless precursor of alkyl viologen as filter agent in photographic film
US3679409A (en) Color diffusion transfer processes and elements for use thereon with incorporated image-forming material impermeable layer
US4003744A (en) Photographic products with photosensitive layers of same spectral sensitivity and different speed
US3647435A (en) Integral negative/positive color diffusion transfer process film unit employing in-situ generated visible light-reflecting agent
US3816125A (en) Photographic products and processes
US3778265A (en) Novel photographic products and processes
US3615421A (en) Novel photographic products and processes
US3575700A (en) Polyvinylamide grafts in spacer layers for color diffusion transfer light sensitive units
US3427158A (en) Novel photographic products and processes
US3573043A (en) Photographic diffusion transfer color process and composite film unit for use therein