JPS6245540B2 - - Google Patents

Description

Claim 1: A layer of a viscous aqueous alkaline processing composition is applied between a first sheet-like element and a second sheet-like element, the first sheet-like element carrying an exposed silver halide emulsion. the second sheet-like element comprises a transparent support carrying an image-receiving layer; the processing composition comprises a light-reflecting pigment and at least one
The optical filter agent is a PH-sensitive phthalein dye; application of the processing composition acts to develop the exposed halogenated emulsion and form a visible image in the image-receiving layer. , the combination of a light-reflecting pigment and an optical filtering agent acts to prevent the transmission of active light to the silver halide emulsion through the processing composition layer during its development; The layer of the second sheet-like element reduces the light absorption capacity of the optical filter agent immediately adjacent the interface between this layer and the treatment composition, reducing the light absorption capacity of the optical filter agent in the treatment composition. Contains a decolorizing agent that is a substantially non-diffusible polyoxyalkylene polymer suitable for reducing the amount of color visible through the transparent support, such that the transmission rate of the treatment composition layer is not substantially altered. A photographic method wherein the surface of the processing composition layer appears substantially white substantially immediately after application of the processing composition. 2. A photographic method as defined in claim 1, wherein said bleaching agent is in a layer above said image-receiving layer. 3. A photographic method as defined in claim 1, wherein the remaining optical filtering agent is decolorized by reducing the PH after a predetermined time following the decolorization of said optical filtering agent adjacent to the interface. 4. A photographic method as defined in claim 1, wherein the combination of said optical filtering agent and said light reflecting pigment is effective to provide a transmission density of at least 6. 5. A photographic method as defined in claim 4, wherein the reflection density of a layer of said processing composition has a reflection density of not greater than about 1 in the absence of said bleaching agent. 6 The above reflection density is approximately
Photographic method as defined in claim 5 not greater than 0.5-0.6. 7. A photograph as defined in claim 1, wherein said optical filtering agent is adhered by gelatin, said first sheet-like element contains gelatin, and said second sheet-like element does not contain gelatin. Method. 8 The bleaching agent reduces the red reflection density of the layer of the treatment composition to approximately 10 seconds after application of the treatment composition.
A photographic method as defined in claim 1, wherein the photographic method is present in a density effective to reduce by not more than 0.35. 9. A photographic method as defined in claim 1, wherein said polyoxyalkylene polymer is a polyoxyethylene polyoxypropylene block copolymer. 10. A photographic method as defined in claim 1, wherein said decolorizing agent is nonyl phenoxyethylene oxide ethanol. 11. A photographic method as defined in claim 1, wherein said bleaching agent comprises a mixture of a polymeric bleaching agent and a second polymer. 12 The polymer-based decolorizing agent is a polyoxyethylene polyoxypropylene block copolymer,
and a photographic method as defined in claim 11, wherein the second polymer is polyvinyl alcohol. 13. A photographic method as defined in claim 1, wherein said optical filtering agent contains long chain substituents. 14 The above optical filter agent is is a PH-sensitive phthalein dye containing groups,
and a photographic method as defined in claim 1, wherein said decolorizing agent is a polyoxyalkylene copolymer. 15 After a predetermined period of time following decolorization of the optical filtering agent adjacent to the interface, reducing the PH of the treatment composition layer to a PH effective for decolorizing the optical filtering agent present in this layer; Photographic method as defined in claim 1, wherein the reduction is effected by a neutralizing layer present on at least one of said sheet-like elements. 16. A photographic process as defined in claim 1, wherein said processing composition contains no more than about 1% by weight of a viscosity-imparting polymer. 17. A photographic method as defined in claim 16, wherein said viscosity-imparting polymer concentration is about 0.8%. 18. A photographic method as defined in claim 16, wherein said viscosity increasing polymer is a polymeric oxime. 19. A photographic method as defined in claim 16, wherein said viscosity increasing polymer is hydroxyethylcellulose. 20. A photographic method as defined in claim 1, wherein said visible image is a dye image. 21. A photographic method as defined in claim 20, wherein said dye is a dye developer. Description This invention relates to photography, and more particularly to photographic processing that occurs outside the camera that exposes the film. Edwin H.
U.S. Pat. A photographic product and method is disclosed. In these products and methods, the final image is viewed through a transparent (support) element against a reflective, ie, white, background. Exposure is through the transparent element and a processing composition is applied to provide a light reflective material to form a white background that allows the final image to be viewed through the transparent support. The light reflective material (referred to in this patent as an opacifying agent) is preferably titanium dioxide, which material also performs an opacifying function. That is, it functions to mask the developed silver halide emulsion so that the transferred image can be seen without interference. This material also helps protect the exposed silver halide emulsion from post-exposure fogging caused by light passing through the transparent image if the exposed film unit is removed from the camera before imaging is complete. Become. U.S. Pat. No. 3,647,437, issued March 7, 1972, to Edwin H. This is prevented by the provision of one or more opacifying dyes, sometimes referred to as absorbing optical filters, which are suitably placed on the film unit after exposure. In a particularly useful embodiment of the invention, the film unit is of the type described in the aforementioned U.S. Pat. No. 3,415,644 and comprises first and second sheet-like elements, the first sheet-like element being The second sheet-like element comprises an opaque substrate carrying a silver emulsion, and the second sheet-like element has an image layer, i.e. a layer suitable for receiving the image-wise distribution of the imageable material initially present in the first sheet-like element. It consists of a transparent support. After exposure, a processing composition suitable for developing the exposed silver halide emulsion and forming the desired image in the image layer is distributed in a thin layer between the two sheet-like elements. The treatment composition contains a reflective pigment such as titanium dioxide and an initial part of the treatment composition.
Contains at least one light-absorbing optical filter, such as a PH-sensitive phthalein dye that is colored at PH. As described in said U.S. Pat. No. 3,647,437, the concentration of said light-reflecting pigment and optical filtering agent(s) is such that the second sheet-like element transmits incident light on its surface. Nevertheless, the concentration is such that the silver halide emulsion is sufficiently opaque to active light so that the film unit can be removed from the camera immediately after the layer of processing composition has been distributed. This opacification system is extremely effective and is used in Polaroid Land SX-70 film. Since the light absorption ability of the optical filter agent is eliminated after this ability is no longer needed,
There is no need to remove the optical filter agent from the film unit. If the optical filter agent is a PH-sensitive dye, such as a phthalein indicator dye, the PH may be reduced by making available an acid-reactive material, such as a polymeric acid, after a predetermined period of time. can be eliminated or bleached. In a preferred embodiment of the opacification system, such as that described in U.S. Pat. and has a reflection density of no greater than about 1. The presence of long chain substituents on the optical filter agent, such as long chain alkoxy groups, is useful to reduce its diffusing ability, thus minimizing diffusion into the image receiving layer. It is recognized that a reflection density of about 1 is very small compared to a transmission density of 6 or more for the same layer. In fact, the reflection density of the treatment composition layer was measured about 30 seconds after distribution and was found to be much lower than 1.
The optical filter agent and titanium dioxide can be used at a concentration such that it is between 0.5 and 0.6. Dye dislocation and development of dye images are seen in opacifying systems, with a reflection density of about 0.5, such temporary coloring of image highlights or white areas, and temporary decolorization of image dyes that have already transferred. is aesthetically undesirable. As mentioned above, when the optical filtering agent is a PH-sensitive dye, a decrease in the PH of the layer containing the optical filtering agent causes it to become decolorized, ie, become substantially colorless. These layers include the light-reflecting pigment layer provided by the processing composition as well as the image-receiving layer and any other layers between the transparent support and the light-reflecting pigment layer through which the final image is viewed.
This PH reduction occurs after a predetermined period of time and reduces the PH level below the pKa value of the optical filter agent. This grace period is necessary to substantially complete development of the silver halide before the incident light is transmitted through the developing silver halide emulsion. Image dyes are soluble and diffusible at the initial pH of processing;
Since it is preferred to be substantially non-diffusive at lower PH, reducing the PH to a suitably low PH after a predetermined period of time reduces the undesirability of the image dye after the desired dye image has been formed. It acts as a very important factor controlling continuous transcription. The desired result of these PH reductions is that a premature reduction in PH also results in an unbalanced color balance, as the premature formation of a white background during processing can prematurely stop image dye transfer. It is recognized that it is only partially acceptable because it can result in a watery, pale image, ie, a low density image. Such an opacification system is "visually clear" when the reflection density, especially the red reflection density, is reduced to about 0.3, i.e. the background provided by the titanium dioxide layer is substantially invisible to the eye. It is recognized, for example, from Figure 8 of US Pat. No. 3,778,265, issued Dec. 11, 1973, to Edwin H. In this particular system shown in Figure 8, the initial reflection density is 0.5 to 0.6 and a reduction in reflection density to 0.3 occurs 5 to 6 minutes after distribution of the treatment composition, resulting in a "visual" Nuke”
(visual clearing). The PH reduction in the examples disclosed herein is accomplished by a neutral polymer suitable for reducing the PH by interaction with the alkaline composition (eg, by hydrolysis). 8th
In the particular system shown, the image-receiving layer is poly-4-
Contains vinylpyridine (mordant). Terry W. Milligan
No. 3,734,727 issued May 22, 1973 to Milligan), an opacifying dye decolorizes the first PH after a predetermined time to ensure that no fog occurs, but image staining or and maintain this second intermediate PH for a second predetermined period of time to reach the desired PH before the PH is reduced to a lower PH that prevents image dye transfer. It is proposed to ensure that image transfer takes place. Maintenance of this second or intermediate PH level is accomplished by providing a buffered PH.
However, the desired reduction in buffered PH takes an undesirably long time. Furthermore, this system is intended to eliminate substantially all opacifying dyes. It is an object of the present invention to provide a diffusion transfer product and method of this type in which the background appears substantially white to the viewer while retaining opacity substantially immediately after the treatment composition is applied. Another object of the present invention is to use an optical filtering agent that is a PH-sensitive phthalein dye, which optical filtering agent is used in combination with an optical filtering agent-containing treatment composition layer and a layer of an image-receiving element that decolorizes when the composition is applied. An object of the present invention is to provide a diffusion transfer product and method using an opacifying system in direct contact with the interface between the image-receiving layer, thus reducing the reflection density of the image-receiving layer while maintaining its transmission density. Yet another object of the present invention is to provide an image receiving element useful in such products and methods having an optical filter agent decolorizing layer over and throughout the image receiving layer. Other objects of the invention will be apparent in part, and in part will become apparent from the following description. Accordingly, the invention relates to several steps and to products having the relationships and sequences of one or more of such steps in relation to each other and the aspects, properties and relationships of the elements illustrated in the following detailed description. and encompasses the range of use indicated in the claims. For a further understanding of the nature and objects of the present invention, reference should be made to the accompanying drawings in the following detailed description, in which: The steps of the monochrome diffusion transfer process are illustrated: exposure, processing and final print. In accordance with the present invention, it has been found that the reflection density imparted by a layer of a treatment composition containing an optical filtering agent that is a light-reflecting pigment and a PH-sensitive phthalein dye can be significantly reduced without significantly reducing its transmission density. discovered. This highly desirable improvement occurs substantially immediately after application of the treatment composition.
a treatment composition and a second in contact with the treatment composition;
by decolorizing the optical filter agent directly adjacent to the interface between the layers of the sheet-like element. In order to effectively render the interface substantially "white" when viewed in reflection, only a very small portion of the applied optical filter agent needs to be bleached. Because reflection density is the result of light being absorbed twice by a given amount of dye, once when it enters and once when it is reflected back, even the decolorization of a few molecules of dye adjacent to the interface Also, reflective optics substantially reduce the reflection density and provide a background such that the image can be seen without reducing the transmission density of the "white" layer to any significant degree. It will be seen that this has an amplifying effect so that the whiteness can be increased. As explained in more detail below, a preferred embodiment of the invention provides a "decolorizing" layer between the image-receiving layer and the layer of processing composition. The bleaching layer contains a substantially non-diffusible adjuvant suitable for bleaching the small concentration of optical filter agent present immediately adjacent the interface between the processing composition and the bleaching layer. It is an important feature of the present invention that this bleaching is substantially limited to the optical filter agent that is present immediately adjacent the interface between the bleaching layer and the treatment composition. Even if the bleaching layer is relatively thin, it is also important to prevent the optical filter agent from diffusing into the image-receiving layer where it can react with the mordant and form "new molecular species" that lose their color only at low pH. This is a feature of the invention.
Such new molecular species have e.g. lower pKa
and remain colored until the pH is reduced to a level below that required for bleaching. It is another feature of the invention that the remaining optical filtering agent can, and preferably is, decolored or bleached by subsequent PH reduction. As mentioned above, the present invention first involves treating an exposed photosensitive silver halide material with a processing composition distributed between two sheet-like elements, one of which contains the photosensitive material. This invention relates to a photographic method by which a desired image can be obtained. The treatment composition is applied without contacting or wetting the outer surfaces of the stacked elements and remains in and between the two sheet-like elements, thus leaving the outer surfaces dry. A film unit or film pack is provided. The treatment composition is viscous;
Dispensing from single-use rupturable containers is preferred; such pressurized rupturable processing containers are often referred to as "pots." The final image can be black and white, monochrome or polychromatic in relation to the object and is either negative or positive. The present invention is particularly, but not uniquely, capable of providing 1
It is held as a stack and the desired image is placed in one of the stacks.
Suitable for facilitating off-camera processing of film units visible through the surface. In the diffusion transfer method within the present invention, the diffusible image-providing material can be a complete dye or a dye intermediate, such as a color coupler. A preferred embodiment of the present invention is a dye developer, i.e., a silver halide developer and dye as described in U.S. Pat. No. 2,983,606 issued May 9, 1961 to Howard G. Rogers. Use compounds that are both. As is now well known, the dye developer becomes fixed or precipitated in the developed areas as a result of development of the latent image. In the unexposed and partially exposed areas of the emulsion,
The dye developer is non-reactive and diffusive, thus providing an imagewise distribution of diffusible unoxidized dye developer in the processing composition as an effect of point-to-point level exposure of the silver halide emulsion. . At least a portion of this imagewise distribution of unoxidized dye developer is transferred by imbivision to the laminated image receiving layer to provide a developed image reversal or positive color image. Preferably, the image receiving layer contains a mordant for the transferred unoxidized dye developer. Said U.S. Patent No.
No. 2983606 and No. 3415644, the image-receiving layer support and any other layer intermediate the support and the image-receiving layer are transparent and the developed silver halide emulsion ( The image-receiving layer may be transferred if a processing composition containing a substance, such as a white pigment, effective for masking the silver halide emulsion(s) is applied between the image-receiving layer and the silver halide emulsion(s). There is no need for separation from the stacked relationship in contact with the photosensitive element after imaging. As mentioned above, dye developers are compounds that have both a dye chromophore system and a silver halide developing functional group in the same molecule. The term "silver halide development functional group" means a group suitable for developing exposed silver halide. A preferred silver halide development functional group is a hydroquinolyl group. Edwin H. Rand and Howard
No. 3,345,163, issued Oct. 3, 1967, to G. Rogers, and as disclosed in said U.S. Pat. When used, polychromatic images can be obtained. A suitable arrangement of this type is such that each emulsion has a red-sensitive halogenated emulsion layer, a green-sensitive halogenated emulsion layer and a blue-sensitive halogenated emulsion layer each having, for example, a cyan dye developer, a magenta dye developer and a yellow dye developer, respectively. Includes a support carrying a silver emulsion layer. The dye developer can be used in the silver halide emulsion layer, for example in the form of grains, or it can be placed in a layer behind a suitable silver halide emulsion layer (eg a layer of gelatin). Each set of layers of dye developer combined with silver halide emulsion is separated from another set of layers by a suitable interlayer. In some cases, it may be desirable to combine a yellow filter before the green-sensitive emulsion and place such a yellow filter in an intermediate layer. However, if the yellow dye developer has suitable spectral properties and is present in a state capable of acting as a yellow filter, the separate yellow filter can be omitted. For convenience, the remainder of the description of the invention will be directed to positive transfer images using dye developers. Reference is now made to the accompanying drawings, which illustrate aspects of the invention:
Like numbers indicate like parts. Referring to the drawings, stages A, B, and C depict respective schematic cross-sections of imaging, processing, and final printing of one embodiment of the present invention. For ease of understanding, the figures illustrate the formation of monochrome images using a single dye developer. Stage A
is a photosensitive element 30 in a laminated relationship with an image receiving element 32;
, and the application of pressure such as by passing the rupturable container 16 (containing the opaque treatment composition 17) through a pair of pressure application rolls or other pressure application means (not shown) It is positioned between the elements to release its contents. Photosensitive element 30 consists of an opaque support carrying a layer 12 of dye developer with a silver halide emulsion layer 14 coated over layer 12. Image receiving element 32 comprises a transparent support carrying in order a polymeric acid layer 22, a spacer layer 20, an image receiving layer 18 and a decolorizing layer 26. Exposure of the silver halide emulsion layer is through the transparent support 24 and the layers carried thereon, namely the polymeric acid layer 22, the spacer layer 20, the image receiving layer 18 and the decolorizing layer 26. These layers may also be transparent so that light entering such film units through camera exposure or lens systems will be exposed to the outside or exposed surface 2 of the transparent support 24.
Place it in the camera so that it is incident on 4a.
After exposure, the film unit is advanced between suitable pressure-applying components to rupture the container 16, thereby releasing the opacifying treatment composition and distributing the layer 17a thereof, thus designated herein as processing step B. A laminate of a photosensitive element 30 and an image receiving element 32 is formed, each support of which provides an outer layer of the laminate (illustrated in step B). The opaque treatment composition contains a film-forming polymer, a white pigment, and has an initial PH at which one or more optical filter agents contained therein are colored; ) is selected such that the activity for the particular silver halide emulsion (or emulsions) exhibits appropriate light absorption, ie, optical density, over a range of wavelengths of light. As a result, room or ambient light within this wavelength range is incident on the transparent support surface 24a and transmitted across the transparent support and the transparent layer carried thereon in the direction of the exposed silver halide emulsion 14a. is absorbed,
Exposure after photographic exposure is thus avoided and silver halide emulsion 14a is developed. In the exposure and development zone, the dye developer is oxidized as a result of silver halide development and passivation. The unoxidized dye developer having a combination of undeveloped and partially developed areas therein remains mobile;
It is imagewise transferred to the image-receiving layer 18 and imparts a desired positive image thereto. Image receiving layer 18 and spacer layer 20
Penetration of the processing composition into the polymeric acid layer 22 through the processing PH performs the necessary development and image transfer, and also causes the optical filter agent(s) to be in colored form within the processing composition layer 17a and This layer 17
It is controlled to maintain a high enough level to be retained on the silver halide emulsion on side a. Thereafter, the reduction in PH resulting from the penetration of the alkali into the polymeric acid layer 22 acts to reduce the PH to a level that converts the optical filter agent into a colorless form. Absorption of water from the applied treatment composition layer 17a results in a solidified film consisting of the film-forming polymer and white pigment dispersed therein, thus providing the reflective layer 17b. This reflective layer 1
7b also serves to laminate the photosensitive component 30 and image receiving component 32 together to form the final laminate (stage C). The positive transfer image of the dye developer present in the image-receiving layer 18a provides a substantially white background for the dye image and also contains the developed silver halide emulsion 14b and the dye developer immobilized therein. a reflective layer 17 that effectively masks dye developer remaining in the dye developer layer 12 from view;
b background, seen through the transparent support 24 and the intermediate transparent layer. The optical filtering agent is retained within the final film unit stack and is preferably colorless in its final form, i.e., exhibits no visible absorption that would degrade the transferred image or the white background for the image provided by reflective layer 17b. It is something. Optical filtering agents can also be carried in reflective layers under these conditions and can contain "anchor" or "ballast" groups to control their diffusion into adjacent layers. Some optical filtering agents can be diffused into the photosensitive component and the reflective layer 1
7b may be retained by gelatin or other material present on the silver halide emulsion; an optical filter retained in the photosensitive component 30 may be effectively masked by the reflective layer 17b to retain either color. The final state may be colorless or colored. In a preferred embodiment, the image-receiving element does not contain gelatin; the photosensitive element contains gelatin, and the optical filtering agent(s) is a PH-sensitive phthalein dye. In this embodiment, exposure is through the image receiving element. This is particularly useful, especially when the photosensitive element and image receiving element are bonded together, as shown in US Pat. Nos. 3,415,644 and 3,647,437, which is the preferred embodiment It will be appreciated that the element may be initially placed outside the exposure path and stacked with the photosensitive element after exposure. A light-absorbing optical filtering agent, preferably a PH-sensitive dye such as an indicator dye, is positioned and/or constituted so as not to interfere with the photographic exposure, but during post-exposure processing the exposed silver halide emulsion and the transparent support. and the emulsion is placed so as to absorb light that could cause fog on the exposed emulsion. Furthermore, the optical filter agent is positioned and/or configured after processing so as not to interfere with viewing the desired image a short time after the image is formed. In a preferred embodiment, the optical filtering agent is initially included in the treatment composition in colored form together with the light-reflecting material, such as titanium dioxide. The concentration of the indicator dye, in combination with the other interlayer silver halide emulsion layer(s) and the incident radiation, prevents non-imagewise exposure, i.e. fog, due to incident actinic light during the performance of certain photographic processes. It is selected to provide the necessary optical transmission density. The transmission and indicator dye concentrations required to provide the necessary protection from incident light are determined by U.S. Pat.
3,647,437 as a function of film speed or sensitivity, processing time, expected incident light intensity, etc., for any photographic process. It will be appreciated that a particular transmission density is not necessary for all portions of the spectrum. In wavelength ranges corresponding to the low sensitivity of the particular photosensitive material, low concentrations are sufficient. In particularly useful embodiments, the light-absorbing dye is highly colored at the PH of the treatment composition, eg, 13-14, but does not substantially absorb visible light at lower PHs, eg, below 10-12. Phthalein dyes having a pKa of about 13-13.5 are particularly suitable; many such dyes are described in the aforementioned US Pat. No. 3,647,437. This PH reduction can be effected by an acid-reactive agent suitably located in the film unit, for example in the layer between the transparent support and the image-receiving layer, as detailed below. Mixtures of light-absorbing substances can also be used, thus covering all the criticalities of visible and near-visible light to which the silver halide emulsions used, such as panchromatic black-and-white silver halide emulsions or multicolor silver halide light-sensitive elements, can be exposed. It will be appreciated that absorption is achieved in the target area. Many dyes, such as phthalein dyes, which change from colored to colorless as a result of PH reduction are known, and the appropriate selection to suit the particular conditions of a given process and film unit is within the skill of those skilled in the art. such dyes are often referred to in the chemical and related industries as indicator dyes. In the present invention, the bleaching agent is a neutral polymeric material such as a polyoxyalkylene polymer, a polyether polymer, and can be used by itself or mixed with another polymer. The bleaching agent should be substantially non-diffusive from the bleaching layer into the processing composition, thus avoiding premature fading of the optical filter agent present in the processing composition. Therefore, its molecular weight should be appropriately selected as described below. The ability of a given decolorizer to decolorize a particular optical filtering agent(s) can be readily determined by the following method: Dissolving the optical filtering agent in gelatin in 1.5 molar aqueous potassium hydroxide and testing. Make an approximately 0.01% by weight optical filter agent solution in the tube. Add the test decolorizer in small portions to this test tube. Decolorizers that decolorize or substantially reduce the visible absorption of the optical filter agent when added to potassium hydroxide in an amount less than about 35 times (by weight) the concentration of the optical filter agent in the solution are preferred. These eliminate the need to use undesirably high bleaching layer coverages, such as thicknesses that undesirably slow or reduce image dye transfer. The following table shows that the test tube test described above was carried out using a polyoxyethylene polyoxypropylene block copolymer (average molecular weight approximately 12,500) commercially available from BASF Wyandotte under the trade name "Pluronic F-127". The results obtained when the method was carried out are shown. Similar results were obtained using a polyoxyethylene polymer commercially available from GAF under the trade name "Igepal CO-890" (Igepal). obtained using.

【table】

【table】

Table: The mechanism by which decolorization occurs in the test is not completely understood. It was determined that addition of Pluronik F-127 or Igepar CO-890 did not change the PH. It is clear that the presence of long chain substituents on the phthalein dye significantly reduces the amount of polyether required to effect decolorization. base It is also clear that phthalein dyes with . Experiments have shown that, in at least some cases, decolorization of PH-sensitive optical filter agents in alkaline solutions is the result of the decolorizer forming complexes with PH-sensitive dyes, and that such complexes
It was shown to exhibit a higher apparent pKa than sensitive dyes. This complexation is believed to involve an alkaline cation, such as K ⁺ . When cationic bonds increase bulk or polarity, the apparent
The pKa moves towards higher levels, i.e. "bleaching" occurs without reducing the pH. The polyethers that have been found to be useful have cationic binding properties, and when many cations bind the polyether or other polymer, the bleaching agent becomes a "supercation," reducing the appearance of the phthalein dye. change the pKa of As noted above, the use of polyoxyethylene polyoxypropylene block copolymers has been found to be particularly useful in the practice of this invention. Block copolymers such as It can be shown as Changing the ratios of a, b and c changes the hydrophobic-hydrophilic balance of this block copolymer, and such changes are valuable in the practice of this invention. Product name: Carbowax
Although other polyoxyalkylene polymers such as commercially available high molecular weight polyethylene glycol (6000 molecular weight) may also be used, the block copolymers described above are more effective and preferred. The following examples illustrate the invention without limiting it. All parts and percentages are by weight unless otherwise specified. Example 1 As a cyan, magenta and yellow dye developer, Use a multicolor photosensitive element, gelatin undercoat 4
Made by applying the following layers to a mill opaque polyethylene terephthalate film base: 1 approximately 69 mg/ft ² of dye and approximately 25 mg/ft ² of gelatin
2-phenylbenzimidazole and about 6.3 mg/ft ^{2 of} 4'-methylphenylhydroquinone.
a layer of cyan dye developer dispersed in gelatin; 2. a red-sensitive gelatinoiodine-silver bromide emulsion coated at a coverage of approximately 120 mg/ft ² silver and approximately 72 mg/ft ² gelatin; 3 approximately 232.8 mg copolymer. 60-30-4-6 of butyl acrylate, diacetone acrylamide, styrene and methacrylic acid coated with a coverage of about 7.2 mg/ft ^{2 and} polyacrylamide.
Copolymer and polyacrylamide layer; 4 dye approximately 60 mg/ft ² and gelatin approximately 42 mg/ft ²
a layer of magenta dye developer dispersed in gelatin applied at a coverage of 2-phenylbenzimidazole and about 21 mg/ ^ft2 ; 5 about 74 mg/ ^ft2 silver and about 36 mg/ ^ft2 gelatin; green-sensitive gelatinoiodine-silver bromide emulsion coated at a coverage of about 127 mg/ft ² of copolymer and about 8.1 mg/ft ² of polyacrylamide and about succinic aldehyde.
A layer containing the copolymer and polyacrylamide used above in layer 3, applied at a coverage of 6.6 mg/ft ² ; 7 about 90 mg/ft ² of dye and about 42 mg/ft ^{2 of} gelatin.
a layer of yellow dye developer dispersed in gelatin, coated at a coverage of 2-phenylbenzimidazole and containing about 19 mg/ft ² ; about 119 mg/ft ² silver, about 62 mg gelatin/ft ² and
4′-Methylphenylhydroquinone approx. 19mg/ft ²
a blue-sensitive gelatinoiodine-silver bromide emulsion layer containing 4′-methylphenylhydroquinone, coated at a coverage of about 45 mg/ft ² of gelatin;
A layer of gelatin containing approximately 4 mg/ft ² of carbon black. The following layers are applied in sequence to a clear 4 mil polyethylene terephthalate film base to form the image receiving element: 1 A portion of polyethylene/maleic anhydride copolymer at a coverage of about 2500 mg/ft ² as a polymeric acid layer. A mixture of butyl ester and polyvinyl butyral in a ratio of about 9:1; 2 60-30- of butyl acrylate, diacetone acrylamide, styrene and methacrylic acid.
4-6 copolymer and polyvinyl alcohol in a ratio of about 45:0.7 and a coverage of about 450 mg/ ^ft2 ; and 3.
Image-receiving layer containing a 2:1:1 mixture of a graft copolymer of 4'-vinylpyridine and vinylbenzyltrimethylammonium chloride (2.2:1:2.2 ratio) at a coverage of about 300 mg/ft ² . Approximately 100 mg/ft ² of a 70:30 mixture of Pluronic F-127 polyoxyethylene polyoxypropylene block copolymer and polyvinyl alcohol is applied as a decolorizing layer over this image-receiving layer. The photosensitive component is exposed and then an aqueous alkaline processing composition is placed on one end of the image receiving component and the container is tacked with pressure sensitive tape with a rupturable container fixedly mounted on each leading edge of both components. Compressive pressure is applied to rupture the seal at the end of the container, distributing its contents between the bleaching layer and the gelatin overcoat layer of the photosensitive component. The exposure is carried out to provide a partial "white" exposure, ie all three silver halide layers are sufficiently exposed so that the corresponding areas of the positive transfer image are "white". The aqueous alkaline treatment composition consists of the following ingredients:

【table】

Table: An approximately 0.0030 inch thick layer of treatment composition was distributed between a pair of pressure rolls in the light direction. The resulting laminate is held together to yield a multicolor integrated negative-positive reflection print exhibiting good color quality and separation. A control was treated in the same manner, differing only in the absence of a bleaching layer. The red, green and blue reflection densities of the "white" portions of the transferred image were measured at the above-mentioned intervals beginning 10 seconds after application of the treatment composition.

【table】

As is evident from the above comparison, the use of a bleaching layer reduces the reflection density attributable to the optical filtering agent in 10 seconds to the density obtained in the absence of this layer which would take 120 seconds. Example 2 The method described in Example 1 was repeated using the same yellow and cyan dye developers and formula of magenta dye developer and the following layers were applied to a gelatin-primed 4 mil opaque polyethylene terephthalate film base: 1 about 630 mg/m ² of dye, about 391 mg/ft ² of gelatin,
N-n-dodecylaminopurine approx. 280mg/m ²
and 4′-methylphenylhydroquinone approx. 88
A layer of cyan dye developer dispersed in gelatin applied at a coverage of mg/m ² ; 2 about 1054 mg/m ² silver and about 6324 mg gelatin/m ²
Red sensitive gelatinoiodine silver bromide emulsion coated at a coverage of 3; 60-30-4- of butyl acrylate, diacetone acrylamide, styrene and methacrylic acid coated at a coverage of about 1076 mg/m ² 6 a layer of a 95:5 mixture of copolymer and polyacrylamide; 4 about 648 mg dye/m ² and about 324 mg gelatin/m ²
a layer of magenta dye developer dispersed in gelatin, coated at a coverage of 5; a green-sensitive gelatinoiodine silver bromide emulsion coated at a coverage of about 749 mg/m ² of silver and about 330 mg/m ² of gelatin; ; 6 Layer 3 contains the copolymer and polyacrylamide used above in a ratio of 91:9, about 1816 mg/
7 layers applied with a coverage of m ² ; 7 dye approx. 659 mg/m ² , gelatin approx. 318 mg/m ² and N-n-dodecylaminopurine approx. 108 mg/m 2
A layer of yellow dye developer dispersed in gelatin applied at a coverage of m ² ; 8 blue-sensitive gelatinoiodine bromide applied at a coverage of about 990 mg silver/m ² and about 495 mg gelatin/m ² a silver emulsion layer; and 9. a layer of gelatin coated at a coverage of approximately 320 mg gelatin/m ² . Using the same method and treatment composition as in Example 1 and receiver component containing a bleaching layer, the reflection densities of the following "white" areas were measured after the indicated seconds of application of the treatment composition: Red Green Blue 10 seconds 37 31 32 20 seconds 34 30 30 30 seconds 34 30 30 40 seconds 34 30 30 Example 3 A receiver element found useful in the practice of the invention was as described in Example 1, except that the timing layer was Hydroxypropylcellulose [Klucel J12HB, Hercules
Inc.) and about 4 parts polyvinyl alcohol to form a layer about 0.27 mil thick. EXAMPLE 4 Receiving elements found to be useful in the practice of this invention were made by coating a transparent 4 mil polyethylene terephthalate film base with the following layers: 1 about 2450 mg/ft ² as a polymeric acid layer. A mixture of a partial butyl ester of a polyethylene/maleic anhydride copolymer and polyvinyl butyral in a ratio of approximately 9:1 in terms of coverage; 2 60-30- of butyl acrylate, diacetone acrylamide, styrene and methacrylic acid.
4-6 copolymer and polyvinyl alcohol in approx.
a timing layer with a coverage of about 300 mg/ft ² containing in a 45:0.7 ratio; 3 a graft copolymer of 4-vinylpyridine and vinylbenzyltrimethylammonium chloride on hydroxyethyl cellulose in a 2.2:1:2.2 ratio 300 mg/ft ² and a small amount of a curing agent; and 4. Pluronic F-127 polyoxyethylene polyoxypropylene block copolymer 70 mg/
ft ² and a decolorizing layer consisting of 30 mg/ft ² of polyvinyl alcohol. In some embodiments of the invention, it has been found that the color balance of the transferred image can be improved when the processing composition contains small amounts of N-methylimidazole, for example 1-1.5%. It will be appreciated that the polyoxyalkylene polymers contemplated for use as bleaching agents in accordance with the present invention are waxy materials that form relatively soft coatings when used alone. For this reason, it is often desirable to mix the polyoxyalkylene polymer with another polymer so that it is not removed during film manufacturing or photographic processing. A particularly useful polymer for this purpose is polyvinyl alcohol. Such mixed polymer bleaching agents are particularly useful in embodiments where positive and negative parts are temporarily laminated prior to distribution of the treatment composition as described above, thus making each part less susceptible to the bleaching agent. It can be delaminated by the treatment composition without any delamination. The concentration of bleaching agent that is effective for any particular photographic system can be readily determined by routine experimentation. In the above example, the bleaching agent is Pluronic F-
127 polyoxyethylene polyoxypropylene block copolymer and polyvinyl alcohol and was applied at approximately 100 mg/ft ² . As an indication of the wide range of concentrations that can be used, it may be pointed out that good results were also obtained applying the same polymer mixture at about 25 mg/ft ² . In some embodiments of the invention, the positive component 32 and the negative component 30 are temporarily laminated such that the bleaching layer 26 is in optical contact with the outer layer of the negative component 30. This bond must be of such a nature that the layers can be easily separated by distribution of the treatment composition following rupture of the pot 17. A particularly useful method for making such temporary laminations is polyethylene glycols, such as Union Carbide.
The solution is to apply an aqueous solution of polyethylene glycol having a molecular weight of about 6000, such as that commercially available from Carbide Corporation under the registered name "Carbowax 6000". The use of such polyethylene glycols is described in US Pat. No. 3,793,023, issued February 19, 1974 to Edwin H. Rand, which may be consulted. A particularly useful composition for making such temporary laminations is a 50:50 mixture by weight of Carbowax 6000 and Pluronic F-127. In certain preferred embodiments of the invention, the positive part 32 and the negative part 30 are temporarily held in a stacked relationship without being stacked together. In such embodiments, the bleaching layer also serves to prevent blocking of the positive and negative components of the integrated film unit during storage prior to its use. It is well known in the art that processing compositions for camera processing should include viscosity increasing polymers of the type that form relatively stiff and stable films when the composition is developed and dried. High molecular weight polymers are preferred and include cellulosic polymers such as sodium carboxymethylcellulose, hydroxyethylcellulose and hydroxyethylcarboxymethylcellulose. One more
One class of useful viscosity increasing polymers includes the oxime polymers described and claimed in Lloyd, D. Taylor, co-pending application Ser. No. 894,545, filed April 7, 1978. Suitable oxime polymers include polydiacetone acrylamide oxime as well as copolymers such as grafts of diacetone acrylamide oxime on hydroxyethylcellulose. Decolorization of the optical filtering agent immediately adjacent the interface is achieved when the viscosity increasing polymer is present at about 1% by weight or less, such as in the example above, about 0.8% by weight or less.
It has been found to be particularly effective when % by weight. Neutralizing layers such as polymeric acid 22 are well known in the art and are described, for example, in the aforementioned U.S. Pat. No. 3,415,644.
No. 3573043 and No. 3647437. In the test tube screening test described above, the amount of water present, even at a ratio of 100:1, is sufficient to dissolve all of the added polyoxyethylene polyoxypropylene block copolymer. Polyoxyalkylene bleaching agents must be in solution in order to bleach phthalein dyes, and one factor that helps limit bleaching in photographic processing to the optical filtering agents directly adjacent to the interface is the ability to remove color from the applied processing composition. It is believed that the amount of water available is too low to dissolve most of the polyoxyalkylene polymer in the bleaching layer. The concentration of the bleaching agent is such that, in the absence of a PH-neutralizing mechanism such as a polymeric acid layer, the bleaching agent is insufficient to bleach or "bleed out" all of the optical filter material present. will be understood. That is, if the polymeric acid layer is omitted,
Although the optical filter agent adjacent to the treatment composition interface is decolorized, it is observed that after time the color of the optical filter agent appears, probably due to subsequent diffusion of the optical filter agent. Instead of using a polymeric acid layer adjacent to the image-receiving layer as in the previous examples, such a polymeric acid layer or a second such polymeric acid layer can be placed adjacent to the support carrying the photosensitive layer. It can also be placed. The present invention is applicable to a wide variety of photographic methods, as will be readily apparent to those skilled in the art. Dye developers are suitable image-providing materials, as described above, and constitute an example of an initially diffusible image-dye-providing material. Other useful dye image-providing materials are initially diffusible dyes, silver halide, which are themselves useful as image dyes and which couple with the oxidation products of silver halide developers to produce non-diffusible products. An initially diffusive color coupler which couples with the oxidation products of the developer to form an image dye, reacts with the oxidation products of the silver halide developer, as by coupling or alternating-oxidation, to form an image dye. Includes initially non-diffusible compounds that liberate diffusible dyes useful as image dyes. The final image may be formed as a result of diffusion transfer of a soluble complex of undeveloped silver halide, in which case the image may be silver, as is well known. In another dye release system, a soluble silver complex formed from undeveloped silver halide can be used to perform a splitting reaction to release the dye or dye intermediate for transfer. Since these imaging methods are well known and do not themselves form part of the present invention, there is no need to elaborate on them here. It will be appreciated that the transferred image may be negative or positive relative to the object as a result of the particular photographic method used. The silver halide emulsions can be negative-working or positive-working (eg, internal latent image) as appropriate for the particular imaging system. For convenience, the disclosures of the aforementioned US Pat. Nos. 3,415,644, 3,573,043 and 3,647,437 are specifically incorporated herein. The invention is not limited thereto, as certain modifications may be made in the products and methods described above without departing from the scope of the invention encompassed herein, and which will be apparent to those skilled in the art. And,
It is intended to cover changes and modifications that are within the spirit of the invention and the scope of the appended claims.