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
  • G03C8/02—Photosensitive materials characterised by the image-forming section
  • G03C8/08—Photosensitive materials characterised by the image-forming section the substances transferred by diffusion consisting of organic compounds
• • 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
  • G03C8/02—Photosensitive materials characterised by the image-forming section
  • G03C8/08—Photosensitive materials characterised by the image-forming section the substances transferred by diffusion consisting of organic compounds
  • G03C8/10—Photosensitive materials characterised by the image-forming section the substances transferred by diffusion consisting of organic compounds of dyes or their precursors
  • G03C8/12—Photosensitive materials characterised by the image-forming section the substances transferred by diffusion consisting of organic compounds of dyes or their precursors characterised by the releasing mechanism
  • G03C8/14—Oxidation of the chromogenic substances
  • G03C8/16—Oxidation of the chromogenic substances initially diffusible in alkaline environment
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10S430/00—Radiation imagery chemistry: process, composition, or product thereof
  • Y10S430/156—Precursor compound
  • Y10S430/158—Development inhibitor releaser, DIR

Definitions

• the present invention is concerned with photography and, more particularly, with color diffusion transfer processes.
• One object of the present invention is to provide processes and products for improving the color quality and the density of diffusion transfer images produced by diffu sion transfer processes employing dye developers.
• Another object of this invention is to provide processes and products useful in diffusion transfer processes, whereby further development of developable silver halide is restrained, and in a preferred embodiment, undeveloped developable silver halide is rendered substantially undevelopable, after a predetermined period, thereby providing diffusion transfer images of improved density and color quality.
• the invention accordingly comprises the processes involving the several steps and the relation and order of one or more of such steps with respect to each of the others, and the products possessing the features, properties and the relation of elements which are exemplified in the following detailed disclosure, and the scope of the application of which will be indicated in the claims.
• a photosensitive element containing a silver halide emulsion and a dye developer is exposed and a liquid processing composition is applied thereto, for example, by immersing, coating, spraying, flowing, etc., in the dark.
• the exposed photosensitive element is superposed prior to, during or after the application of said liquid processing composition on a sheetlike support element which may be utilized as the image-receiving layer.
• the photosensitive element contains the dye developer in a stratum positioned behind the silver halide emulsion layer with respect to the incident actinic light, and the liquid processing composition is applied to the photosensitive element by being spread in a relatively thin layer as the photosensitive element is brought into superposed relationship with an image-receiving element.
• the dye developer may be utilized in the processing composition where monochromatic images are desired, use of a negative containing a plurality of silver halide emulsions for forming multicolor images requires that at least the dye developers employed in the development of the innermost emulsion layer or layers be initially contained in the photosensitive element.
• the dye developer employed with the outermost photosensitive emulsion layer may, if desired, be contained in the processing composition, although in a preferred embodiment, the dye developer associated with the outermost emulsion layer is also contained in the photosensitive integral multilayer element. Since the outermost emulsion layer is customarily a blue-sensitive emulsion, use of a yellow dye developer in a layer behind the blue-sensitive emulsion makes possible the omission of the conventional yellow filter layer required to facilitate the desired selective exposure of the underlying redand green-sensitive emulsion layers. Products and processes for effecting the formation of multicolor images by the use of integral multilayer negatives are disclosed and claimed in the copending United States application of Edwin H. Land and Howard G.
• the liquid processing composition permeates the emulsion to initiate development of the developable silver halide.
• the dye developer associated with each of the silver halide emulsion layers is immobilized or precipitated in the developed areas as a consequence of this development. This immobilization is apparently, at least in part, due to a decrease in the mobility or solubility of the oxidation product of the dye developer as compared with the unoxidized dye developer. This immobilization may also be due in part to a localized reduction in the alkali concentration as a function of the development.
• the unreacted dye developer associated with undeveloped and partly developed areas of the emulsion is diffusible, and thus an imagewise distribution of mobile unoxidized dye developer is formed as a function of the point-to-point degree of exposure and development of the silver halide emulsion. At least part of this imagewise distribution of diffusible, unoxidized dye developer is transferred by imbibition to the superposed image-receiving layer or element, said transfer being effected sufficiently to the exclusion of the less mobile oxidized dye developer to create a visible transfer image on the image-receiving layer.
• processes of this type employing an integral multilayer negative processed with a common processing composition necessarily require that unoxidized dye developer diffusing from an underlying emulsion to the superposed image-receiving layer must pass through at least one other overlying photosensitive silver halide emulsion. If the unoxidized dye developer diffusing from the underlying layer enters an area of the overlying emulsion containing developable silver halide, there is as much likelihood that the diffusing dye developer from the underlying emulsion will react as that the dye developer associated with said overlying emulsion will react.
• a photosensitive integral multilayer element containing red-sensitive, greensensitive and blue-sensitive silver halide emulsions coated in that order on a common support.
• These silver halide emulsions have associated therewith, respectively, a cyan dye developer, a magenta dye developer, and a yellow dye developer either in a layer behind the emulsion or in the emulsion layer.
• a cyan dye developer a magenta dye developer
• a yellow dye developer either in a layer behind the emulsion or in the emulsion layer.
• magenta dye developer has substantially completed the development of the developable green-sensitive silver-halide prior to the arrival of the unoxidized cyan dye developer, no harm will be done.
• the migrating cyan dye developer diffuses into the green-sensitive emulsion layer while appreciable undeveloped developable greensensitive silver halide is still present, said cyan dye developer may react since it will not distinguish between developable silver halides of different color sensitivity. This reaction in the wrong silver halide emulsion may be referred to as cross-talk, and manifests itself in producing transfer images having reduced color separation and in the instance given, less cyan density and probably more magenta density than the actual exposure would indicate should be present in the transfer image.
• this control may be accomplished by incorporating in a layer of either the photosensitive element or the image-receiving element, or in some instances in the processing composition, a reagent which is made available to the developable silver halide of a given emulsion layer only after a predetermined period during which development is effected without interference by said reagent. Since this added reagent effectively restrains, i.e., minimizes, further development of developable silver halide after this predetermined period, suitable reagents employed [for this purpose may be referred to as development restrainers.
• reagents While such reagents frequently will have characteristics similar to reagents commonly referred to as antifoggants, they perform a function herein different from what is normally contemplated as the function of an antifoggant, i.e., their function is not to reduce the fog density in unexposed areas, although under some circumstances, they may also perform this function to a small degree.
• a given reagent may be used in a small concentration in the processing composition wherein it functions as an .a-ntifoggant, and an additional quantity is contained in the photo-sensitive element or in the image-receiving element in a form whereby it is released only after a predetermined period whereupon it acts as a development restrainer.
• Rea-gents which are particularly suitable for use as development restrainers are those which will form products or complexes with undeveloped silver halide, whether exposed or unexposed, but at least with exposed silver halide, which products or complexes are substantially less developable by a silver halide developing agent, e.g., by the dye developer, and which preferably are substantially insoluble, and hence essentially undevelopable, i.e., developable only with difficulty.
• the desired predetermined period during which development is effected without interference is accomplished by incorporating the development restrainer in a chemical form or in a physical location such that its availability to the developable silver halide is limited or restricted, e.g., as a result of the distance through which it must diffuse to reach the developing silver halide, or as a consequence of a significantly lower diffusion rate than said developing agents.
• the development restrainer is at least initially substantially slower in difliusion than the dye developer, as for example, as a result of the inclusion of a relatively long chain alkyl group
• the development restrainer may be positioned in a layer of the multilayer negative, e.g., in the dye layer containing the dye developer or in an interlayer positioned on the side of the dye layer remote from the silver halide emulsion layer.
• a relatively more diffusable development restrainer may be used provided that it is located sufficiently remote physically from the silver halide emulsion layer upon which it is to act, as by incorporation in the image-receiving layer, i.e., in the image-receiving layer itself or in a layer over the image-receiving layer or in a subcoat beneath the image-receiving layer.
• Such development restrainers may also be incorporated in a layer in the photosensitive element provided said restrainer is present in such a form as to be only slowly dissolved by the processing composition. Under some circumstances, the development restrainer may be similarly contained in a coating over the outermost or blue-sensitive silver halide emulsion layer.
• the development restrainers . are employed, in combination, with an ant-ifoggant initially contained in the processing composition and/ or in a layer of the photosensitive element so as to be available for action relatively promptly after the application of the processing compositon.
• antifoggants perform the usual function of an antifoggant, i.e., they minimize the development of silver fog in unexposed and partially exposed areas of the several photosensitive silver halide emulsions and increase the differentiation between exposed and unexposed silver halide by the developing agent.
• the development restrainer may and frequently is a compound of the broad class of reagents frequently referred to as antifoggants.
• development is effected in the presence of one or more auxiliary or accelerating silver halide developing agents as also disclosed and claimed in the previously mentioned copending UnitedStates application Serial No. 748,421.
• auxiliary silver halide developing agents may initiate development by virtue of their relatively greater diffusion rate than the larger dye developer molecule.
• the auxiliary developer is believed to develop a portion of the developable silver hali e, the dye developer being oxidized by reaction with the oxidation product of the auxiliary developing agent.
• benzenoid silver halide developing agents i.e., silver halide developing agents containing a benzene or naphthalene nucleus substituted by at least two hydroxyl, amino, and/or alkylamino radicals so as to be capable of developing exposed silver halide and forming a quinonoid oxidation product, e.g., to'luhydroquinone, phenylhydroquinone, 4'-methylphenylhydroquinone, etc.
• a quinonoid oxidation product e.g., to'luhydroquinone, phenylhydroquinone, 4'-methylphenylhydroquinone, etc.
• auxiliary developing agents is S-pyrazolidones, and preferably 1-phenyl-3-pyrazolidone, and 1-phenyl-4,4- dimethyl-3-pyrazolidone. It will be understood that reference to development of developable silver halide is in tended to include development by the auxiliary developing agent as well as by the dye developer itself.
• an auxiliary developing agent is contained in a layer over the outermost silver halide emulsion, in accordance with the disclosure of our copending United States application, Serial No. 50,850, tiled August 22, 1960.
• the following example illustrates the use of a development restrainer incorporated in an underlying layer of the photosensitive element in a manner whereby its availability to the developing silver halide emulsion is delayed by .a predetermined period, e.g., by the time required to dissolve the development restrainer and, following dissolution, to diffuse to the silver halide.
• a reagent normally used as an antifoggant may also be useful as a development restrainer when used in appropriately larger concentrations.
• Example 1 A photosensitive element was prepared by coating a gelatin-swbcoated cellulose acetate film support with the following coating solutions; proportions being by weight unless otherwise stated:
• a tetrahydrofuran-acetone solution (1 to 1 by volume) comprising 5.5% of 1,4-bis-[B-(2',5'-d-ihydroxyphenyl)isopropylamino]-anthraquinone (a cyan dye developer), about 0.8% of Resoflex 296 (trade name of Cambridge Industries Co., Inc., Cambridge, Mass, for an alkyd resinous plasticizer), 0.4% S-nitrobenzirnidazole, and 2% cellulose acetate hydrogen phthalate.
• the image-receiving element comprised a cellulose acetate subcoated baryta paper which had been coated with an ethanol solution containing 4% of N-methoxymethyl polyhexamethylene adipamide. After an imbibition period of approximately three minutes the image receiving element was separated and contained a positive image of the photographed subject, having improved photographic quality as compared with the image obtained using a similar negative but omitting the S-nitrobenzimidazole from the cyan dye layer.
• the development restrainer may be incorporated in the image-receiving element.
• the following examples illustrate this manner of practicing this invention:
• Example 2 A sheet of subcoated baryta paper was coated with an aqueous solution containing a small amount of acetic acid and comprising:
• Percent Elvanol 72-60 (trade name of E. I. du Pont de Nemours & Co., Wilmington, Delaware, for high viscosity, 100% hydrolyzed polyvinyl alcohol) 2.4 Poly-4-vinylpyridine 2.4 l-phenyl-S-mercaptotetrazole 0.08
• Example 3 An image-receiving layer was prepared as described in Example 2, except that l-phenyl-S-mercaptotetrazole is omitted from the layer of polyvinyl alcohol and poly-4- vinyl pyridine and is contained in a subcoat between the support and said polyvinyl a-lcohol/poly-4-vinyl pyridine receiving layer.
• This subcoat may be prepared using a methanol solution containing 3.5% of l-phenyl-S-mercap- .totetrazole and 1.2% of partially hydrolyzed polyvinyl acetate (Vinylite MA-28l8).
• the transfer images obtained using the image-receiving elements of Examples 2 and 3 show increased maximum density .and improved color separation; in some instances an increase in film speed (exposure index) was also observed with the imagereceiving element of Example 3 as compared with that of Example 2.
• Example 4 An image-receiving layer was prepared by coating a cellulose acetate subcoated baryta paper with a layer containing 4% N-methoxymethyl polyhexamethylene adiparnide in an ethanol solution. A 40% aqueous ethanol solution containing 2% thioacetanilide was then applied to the surface of this image-receiving layer. The image-receiving layer was then dried and employed in a diffusion transfer process using a photosensitive element such as that described in Example 1. The resulting transfer image exhibited increased density and better color separation than if the thioacetanilide were omitted from the image-receiving layer.
• the resulting color transfer image exhibited increased maximum density and improved color separation.
• the multicolor negatives may employ the dye developer molecularly dispersed in a layer of alkali-permeable plastic, or the dye developer may be dissolved in a water-immiscible solvent and dispersed in gelatin to provide the desired dye layer.
• suitable interlayers for the photosensitive element include polyvinyl alcohol or gelatin of appropriate thickness. The use of a .gel-atin inter-layer is particularly advantageous where the dye developer is dispersed in gelatin to provide the dye layer.
• Photosensitive multilayer negative-s having an auxiliary developer incorporated in a gelatin layer over the outermost or blue-sensitive silver halide emulsion layer.
• Photosensitive elements of this type are disclosed and claimed in our copending United States application, Serial No. 50,850, filed August 22, 1960, now US. Patent No. 3,192,- 044, issued June 29, 1965.
• S-nitrobenzimidazole In addition to the illustrated use of S-nitrobenzimidazole, mention may be made of S-methylbenzimidazole, Z-aminobenzimidazole, thioacetanil'ide, Z-mercapto-benzo- .thiazole and benzot-riazole as being particularly useful antifoggants which may be incorporated in the photosensitive element. Where the development restrainer is incorporated in the image-receiving element, l-phenyl-S- mercaptotetrazole has been found to be particularly useful.
• a silver halide solvent e.g., sodium thiosulfate
• improved color separation has been observed where such a silver halide solvent has been used in the absence of a silver precipitating agent in ,the image-receiving layer.
• the dye developers which are used in the processes of this invention as noted above are compounds which contain in the same molecule the chromophoric system of a dye and also a silver halide developing function.
• Preferred dye developers are those comprising hydroxy substituted benzenoid silver halide developing radicals and especially dyes containing hydroquinonyl and catechol silver halide developing radicals.
• Representative dye developers for use in the processes of this invention are disclosed in the previously mentioned copending United States applications, Serial Nos. 748,421 (now US. Patent No. 2,983,606, issued May 9, 1961), 565,135 and other copending applications referred to therein.
• the aqueous processing compositions used in the processes of this invention are alkaline in nature and preferably should have a pH of at least 12. Particularly suitable materials for rendering the processing composition alkaline are sodium hydroxide, potassium hydroxide, diethylamine, etc.
• the processing composition preferably includes .an antifoggant which is available essentially immediately upon permeation of the photosensitive silver halide layer by the processing composition.
• the processing composition may also contain other reagents such as the auxiliary developing agent, stabilizers or preservatives, antioxidants, organic solvents which preferentially increase the solubility of the unox'idized dye developer in the processing composition, etc.
• the process of this invention are especially useful in composite film units intended for use in a Polaroid Land Camera, sold by Polaroid Corporation, Cambridge 39, Massachusetts, or a similar camera structure such, for example, as the camera forming the subject matter of US. Patent No. 2,435,717, issued to Edwin H. Land, on February 10, 1948.
• composite film units comprise a photosensitive element such as the integral multilayer element heretofore mentioned, an image-receiving element, and a rupturable pod containing an aqueous alkaline processing composition.
• the photosensitive element, image-receiving element and pod are so associated with each other that, upon processing, the photosensitive element may be superposed on the image-receiving element, and the pod may be ruptured to spread the aqueous alkaline processing solution between the superposed elements.
• the nature and construction of the I pods and such composite film units are well known in the 8 art; see, for example, US. Patents Nos. 2,543,181 and 2,634,886, issued to Edwin H. Land, as well as the previously noted copending United States applications Serial Nos. 748,421 (now U.S. Patent No. 2,983,606, issued May 9, 1961) and 565,135.
• a development restrainer made available after a predetermined period, may be advantageously used to increase the maximum density of the transfer image in monochrome processes or multicolor processes employing a plurality of separate sets of silver halide emulsions and image-receiving layers.
• hydrolysis of a suitable derivative of the development restrainer is also contemplated to make a development restrainer available after a predetermined period by hydrolysis of a suitable derivative of the development restrainer.
• the hydrolyzable development .restrainer is preferably substantially non-diffusible, and at least substantially less dilfusible in its unhydrolyzed form than in its hydrolyzed form. Hydrolysis of the hydrolyzable development restrainer after a predetermined induction period will thus be an effective way of controlling the availability of the development restrainer and insuring that development is carried out unimpeded by the development restrainer for at least a time sufficient to develop the exposed and developable silver halide to the minimum extent necessary to properly modulate the appropriate dye developer.
• hydrolyzable groups examples include oxalates having various length alkyl groups to obtain the desired induction period prior to hydrolysis and availability of the development restrainer.
• the hydrolyzable development restrainer may be located much closer physically to the appropriate silver halide emulsions than if such development restrainers were initially diffusible.
• the image-receiving layer is preferably located so as to be superposed with the outermost or blue-sensitive silver halide emulsion layer of the photosensitive element and to be carried by its own support, it is also contemplated to have the image-receiving layer carried by the same support as are the photosensitive layers, i.e., on the same side or on the opposite side of the support as the silver halide emulsion layers.
• the image-receiving layer is carried on the same side of the support as are the emulsion layers, the developed and processed emulsion layers are removed from the image-receiving layer by use of suitable techniques, e.g., by the use of appropriate stripping layers.
• the image-receiving layer is located on the opposite side of the support from the photosensitive layers, it may be unnecessary to remove the emulsion layers if the support is opaque or the photosensitive layers are otherwise treated to render them harmless to the viewing of the positive or transfer image contained in the image-receiving layer.
• a process of forming a multicolor image by diffusion transfer comprising (a) exposing a photosensitive element comprising a support carrying, in turn, a layer including a red-sensitive silver halide emulsion, a layer including a green-sensitive silver halide emulsion and a layer inclu-ding a blue-sensitive silver halide emulsion, said silver halide emulsions having associated therewith, respectively, a cyan dye developer, a magenta dye developer and a yellow dye developer, (b) applying an aqueous alkaline processing solution to said photosensitive element to initiate development of exposed silver halide, said dye developers being oxidized and thereby immobilized where development occurs, (c) continuing said development of exposed silver halide for a predetermined period, said predetermined development period being sufficiently long to form an i-magewise distribution of diffusible unoxidized dye developer in undeveloped areas of each of said silver halide emulsion layers as a function of said development, said unoxidized dye developers being
• each of said dye developers is initially contained in a layer positioned between its associated silver halide emulsion layer and sa-id support.
• said photosensitive element includes an alkali-permeable layer containing a benzenoid silver halide developing agent, said alkali-permeable layer being coated over said blue-sensitive emulsion layer.
• said aqueous alkaline processing solution contains an antifoggant eflt'ective to minimize the development of unexposed silver halide during said predetermined period.
• a process of forming a multicolor image by diffusion transfer comprising (a) exposing a photosensitive element comprising a support carrying, in turn, a layer including a red-sensitive silver halide emulsion, a layer including a green-sensitive silver halide emulsion and a layer including a blue-sensitive silver halide emulsion, said silver halide emulsions having associated therewith, respectively, a cyan dye developer, a magenta dye developer and a yellow dye developer, (b) applying an aqueous alkaline processing solution to said photosensitive element to initiate development of exposed silver halide, said dye developers being oxidized and thereby immobilized where development occurs, (0) continuing said development of exposed silver halide for a predetermined period, said predetermined development period being sufiiciently long to form an imagewise distribution of difiiusible unoxidized dye developer in undeveloped areas of each of said silver halide emulsion layers as a function of said development, said unoxidized dye developers
• each of said dye developers is initially contained in a layer positioned between its associated silver halide emulsion layer and said support.
• said photosensitive element includes an alkali-permeable layer containing a benzenoid silver halide developing agent, said alkali-permeable layer being coated over said bluesensitive emulsion layer.
• aqueous alkaline processing solution contains an antifoggant efiective to minimize the development of unexposed silver halide during said predetermined period.

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• Silver Salt Photography Or Processing Solution Therefor (AREA)

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• 0
  • NL NL126854D patent/NL126854C/xx active
  • NL NL268155D patent/NL268155A/xx unknown
• 1960
  • 1960-08-22 US US50849A patent/US3265498A/en not_active Expired - Lifetime
• 1961
  • 1961-08-18 SE SE8336/61A patent/SE315200B/xx unknown
  • 1961-08-21 GB GB30107/61A patent/GB938864A/en not_active Expired
  • 1961-08-21 CH CH974161A patent/CH453073A/fr unknown
  • 1961-08-21 CH CH497866A patent/CH458066A/fr unknown
  • 1961-08-22 DE DEI20436A patent/DE1288911B/de active Pending

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