Claims
- 1. A photographic product which comprises a photosensitive element comprising a plurality of layers including a support, at least two selectively sensitized silver halide emulsion layers, each of said emulsion layers having associated therewith a color-providing compound capable of undergoing cleavage in the presence of an imagewise distribution of silver ions and/or soluble silver complex to liberate a color-providing moiety in an imagewise distribution corresponding to said distribution of silver ions and/or said complex, one of said color-providing compound and said color-providing moiety being diffusible in aqueous alkaline solution and the other being substantially non-diffusible in aqueous alkaline solution, and a scavenger layer containing a scavenger for silver ion and/or soluble silver complex, said scavenger layer being positioned between said two selectively sensitized silver halide emulsion layers, each of said color-providing compounds being a compound containing a group selected from ##STR18##
- 2. A product as defined in claim 1 wherein said selectively sensitized emulsion layers are a red-sensitive emulsion, a green-sensitive emulsion, and a blue-sensitive emulsion, and said color-providing compounds associated with said silver halide emulsions are, respectively, a cyan color-providing compound, a magenta color-providing compound and a yellow color-providing compound.
- 3. A product as defined in claim 2 which includes a first scavenger layer positioned between said red-sensitive and said green-sensitive silver halide emulsions and a second scavenger layer positioned between said green-sensitive and said blue-sensitive silver halide emulsions.
- 4. A product as defined in claim 1 wherein said scavenger layer comprises a silver complexing agent capable of forming a non-diffusible silver complex.
- 5. A product as defined in claim 1 wherein said scavenger layer comprises a silver complexing agent capable of forming a silver complex decomposable to a silver precipitating agent.
- 6. A product as defined in claim 1 wherein said scavenger layer comprises a silver precipitating agent.
- 7. A product as defined in claim 6 wherein said scavenger layer comprises a silver precipitating agent dispersed in a layer of gelatin.
- 8. A product as defined in claim 4 wherein said silver complexing agent is a polymer containing mercapto groups.
- 9. A product as defined in claim 1 wherein each said color-providing compound contains the groups ##STR19##
- 10. A product as defined in claim 10 wherein X is ##STR20##
- 11. A product as defined in claim 10 wherein each said compound is a cyclic compound having a ring system containing up to 20 members and said ##STR21## group is included in the ring.
- 12. A product as defined in claim 11 wherein each said color-providing compound is a thiazolidine.
- 13. A product as defined in claim 1 wherein each said color-providing compound is substantially non-diffusible and said color-providing moiety released therefrom is diffusible in aqueous alkaline solution.
- 14. A product as defined in claim 13 wherein each said color-providing moiety liberated from each said color-providing compound is a diffusible dye.
- 15. A product as defined in claim 14 including a superposed image-receiving layer so positioned as to be capable of receiving by diffusion transfer an imagewise distribution of each said diffusible dye and further including means for applying an aqueous alkaline processing composition in a substantially uniform layer between said silver halide emulsions and said image-receiving layer.
- 16. A product as defined in claim 15 wherein said image-receiving layer is carried on a transparent support and said product additionally includes means for providing a light-reflecting layer between said image-receiving layer and said silver halide emulsions to mask said silver halide emulsions after development thereof and to provide a white background for viewing a dye image in said image-receiving layer.
- 17. A product as defined in claim 16 wherein said silver halide emulsions are adapted to be exposed through said transparent support.
- 18. A product as defined in claim 17 wherein said means for providing an aqueous alkaline processing composition comprises a rupturable container releasably retaining an aqueous alkaline solution of a silver halide developing agent positioned between said image-receiving layer and said silver halide emulsions.
- 19. A product as defined in claim 18 wherein said means for providing a light-reflecting layer comprise a white pigment dispersed in said processing composition.
- 20. A photographic process for forming multicolor images comprising the steps of
- a. exposing a photosensitive element comprising a plurality of layers including a support, at least two selectively sensitized silver halide emulsion layers, each of said emulsion layers having associated therewith, a color-providing compound capable of undergoing cleavage in the presence of an imagewise distribution of silver ions and/or soluble silver complex to liberate a color-providing moiety in an imagewise distribution corresponding to said distribution of silver ions and/or said complex, one of said color-providing compound and said color-providing moiety being diffusible in aqueous alkaline solution and the other being substantially non-diffusible in aqueous alkaline solution, and a scavenger layer containing a scavenger for silver ion and/or soluble silver complex, said scavenger layer being positioned between said two selectively sensitized silver halide emulsion layers, each of said color-providing compounds being a compound containing a group selected from ##STR22## b. applying an aqueous alkaline processing composition to said photosensitive element to provide an aqueous alkaline solution of a silver halide developing agent and a silver halide solvent therein, thereby developing said photosensitive element;
- c. forming in undeveloped areas of each of said emulsions an imagewise distribution of silver ions and/or soluble silver complex; and
- d. contacting said imagewise distribution of silver ions and/or soluble silver complex formed in each of said emulsion with the emulsion's associated color-providing compound thereby forming corresponding imagewise distributions of each of said color-providing moieties.
- 21. A process as defined in claim 20 wherein said selectively sensitized emulsion layers are a red-sensitive emulsion, a green-sensitive emulsion, and a blue-sensitive emulsion, and said color-providing compounds associated with said silver halide emulsions are, respectively, a cyan color-providing compound, a magenta color-providing compound and a yellow color-providing compound.
- 22. A process as defined in claim 21 which includes a first scavenger layer positioned between said red-sensitive and said green-sensitive silver halide emulsions and a second scavenger layer positioned between said green-sensitive and said blue-sensitive silver halide emulsions.
- 23. A process as defined in claim 20 wherein said scavenger layer comprises a silver complexing agent capable of forming a non-diffusible silver complex.
- 24. A process as defined in claim 20 wherein said scavenger layer comprises a silver complexing agent capable of forming a silver complex decomposable to a silver precipitating agent.
- 25. A process as defined in claim 20 wherein said scavenger layer comprises a silver precipitating agent.
- 26. A process as defined in claim 25 wherein said scavenger layer comprises a silver precipitating agent dispersed in a layer of gelatin.
- 27. A process as defined in claim 26 wherein said precipitating agent is cadmium sulfide.
- 28. A process as defined in claim 23 wherein said silver complexing agent is a polymer containing mercapto groups.
- 29. A process as defined in claim 20 wherein each said color-providing compound contains the groups ##STR23##
- 30. A process as defined in claim 29 wherein X is ##STR24##
- 31. A process as defined in claim 30 wherein each said compound is a cyclic compound having a ring system containing up to 20 members and said ##STR25## group is included in the ring.
- 32. A process as defined in claim 31 wherein each said color-providing compound is a thiazolidine.
- 33. A process as defined in claim 20 wherein each said color-providing compound is substantially non-diffusible and each said color-providing moiety released therefrom is diffusible in aqueous alkaline solution.
- 34. A process as defined in claim 33 wherein each said color-providing moiety liberated from each said color-providing compound is a diffusible dye.
- 35. A process as defined in claim 34 wherein a sheet-like element comprising an image-receiving layer is superposed with said photosensitive element and at least a portion of said imagewise distributions of each of said diffusible dyes is transferred to said image-receiving layer to form a color transfer image thereon.
- 36. A process as defined in claim 35 wherein said aqueous alkaline processing composition is distributed in a substantially uniform layer between said image-receiving layer and said silver halide emulsions.
- 37. A process as defined in claim 36 wherein said image-receiving layer is carried on a transparent support.
- 38. A process as defined in claim 37 which includes providing a light-reflecting layer between said image-receiving layer and said silver halide emulsions to mask said silver halide emulsions after development thereof and to provide a white background for viewing the dye image in said image-receiving layer.
- 39. A process as defined in claim 38 wherein said light-reflecting layer is provided by including a white pigment dispersed in said processing composition.
- 40. A process as defined in claim 39 which includes the step of maintaining said photosensitive element and said sheet-like element intact subsequent to processing.
- 41. A process as defined in claim 35 wherein said selectively sensitized emulsion layers are a red-sensitive emulsion, a green-sensitive emulsion, and a blue-sensitive emulsion, and said color-providing compounds associated with said silver halide emulsions are, respectively, a cyan color-providing compound, a magenta color-providing compound and a yellow color-providing compound.
- 42. A process as defined in claim 41 which includes a first scavenger layer positioned between said red-sensitive and said green-sensitive silver halide emulsions and a second scavenger layer positioned between said green-sensitive and said blue-sensitive silver halide emulsions.
- 43. A process as defined in claim 35 wherein said scavenger layer comprises a silver complexing agent capable of forming a non-diffusible silver complex.
- 44. A process as defined in claim 35 wherein said scavenger layer comprises a silver complexing agent capable of forming a silver complex decomposable to a silver precipitating agent.
- 45. A process as defined in claim 35 wherein said scavenger layer comprises a silver precipitating agent.
- 46. A process as defined in claim 45 wherein said scavenger layer comprises a silver precipitating agent dispersed in a layer of gelatin.
- 47. A process as defined in claim 46 wherein said silver precipitating agent is cadmium sulfide.
- 48. A process as defined in claim 43 wherein said silver complexing agent is a polymer containing mercapto groups.
- 49. A process as defined in claim 41 wherein each said color-providing compound contains the group ##STR26##
- 50. A process as defined in claim 49 wherein X is ##STR27##
- 51. A process as defined in claim 50 wherein each said compound is a cyclic compound having a ring system containing up to 20 members and said ##STR28## group is included in the ring.
- 52. A process as defined in claim 51 wherein each said color-providing compound is thiazolidine.
BACKGROUND OF THE INVENTION
This application is a continuation-in-part of our copending U.S. Application Ser. No. 465,694 filed Apr. 30, 1974, now abandoned, which is a continuation-in-part of our U.S. application Ser. No. 317,168 filed Dec. 21, 1972, now abandoned, which in turn is a division of our U.S. application Ser. No. 155,123 filed June 17, 1971 and now U.S. Pat. No. 3,719,489 issued Mar. 6, 1973.
This invention relates to photography, and more particularly, to photographic products and processes for preparing color images utilizing as the dye image-forming material, a color-providing compound capable of undergoing cleavage in the presence of an imagewise distribution of silver ion and/or soluble silver complex to liberate a corresponding imagewise distribution of color-providing moiety, e.g., a dye.
Diffusion transfer photographic processes are now well-known. In preparing silver images according to such processes, an exposed photosensitive element comprising a light-sensitive silver halide emulsion is developed by treating the emulsion with a processing composition comprising an aqueous alkaline solution of a silver halide developing agent and a silver halide solvent. The developable silver halide of the emulsion is reduced to image silver by the developing agent while the silver halide solvent forms an imagewise distribution of a soluble complex with the undeveloped silver halide. This imagewise distribution of soluble silver complex is, at least in part, transferred by imbibition to a superposed image-receiving layer where it is reduced to form a silver transfer image.
Aforementioned U.S. Pat. No. 3,719,489 describes and claims photographic processes employing certain photographically inert compounds which are stable in the photographic processing composition but capable of undergoing cleavage in the presence of the imagewise distribution of silver ions made available during processing of a silver halide emulsion to liberate a reagent, such as, a photographically active reagent or a dye in an imagewise distribution corresponding to that of said silver ions. Depending upon the photographic process and the result it is desired to achieve the inert parent compound may be diffusible or substantially non-diffusible in the processing solution and the reagent liberated also may be diffusible or substantially non-diffusible in the processing composition.
In one embodiment disclosed in the aforementioned patent, color images are produced by using as the photographically inert compounds, color-providing compounds which are substantially non-diffusible in the photographic processing solution but capable of undergoing cleavage in the presence of the imagewise distribution of silver ions and/or soluble silver complex made available in the undeveloped and partially developed areas of a silver halide emulsion as a function of development to liberate a more mobile and diffusible color-providing moiety in an imagewise distribution corresponding to the imagewise distribution of said ions and/or said complex. The subsequent formation of a color image is the result of the differential in diffusibility between the parent compound and liberated color-providing moiety whereby the imagewise distribution of the more diffusible color-providing moiety released in undeveloped and partially developed areas is free to transfer.
Both monochromatic and multicolor images may be produced in this manner. For example, the above-described color-providing compounds may be employed in photographic systems utilizing integral multilayer photosensitive elements comprising at least two selectively sensitized silver halide emulsion strata with associated color-providing material which are processed simultaneously and without separation to provide a multicolor image on a single common image-receiving element.
Among the compounds disclosed as useful in liberating a reagent in the presence of silver ion are sulfur-nitrogen compounds containing the group, ##STR1## wherein X is ##STR2## These compounds may be linear or cyclic in structure, and when cyclic, either or both the S and N atoms may be constituents of the ring. Particularly useful are cyclic compounds containing the group ##STR3## as part of the ring and preferably, the latter. Like 1,3-sulfur-nitrogen compounds, in general, these compounds undergo cleavage in a stepwise fashion between the S atom and the C atom common to the S and N atoms and also between the N atom and the common C atom.
As discussed in the aforementioned patent, sulfur-nitrogen compounds, as exemplified by thiazolidine compounds, exhibit good stability in alkaline media, such as the aqueous alkaline processing compositions employed in conventional "tray" and diffusion transfer photographic processes, and undergo cleavage in the presence of silver ions and/or soluble silver complex made available during processing to release a reagent as a smaller molecule in an imagewise distribution corresponding to the imagewise distribution of silver ions and/or soluble silver complex. For example, thiazolidine compounds release a diffusible dye such that a diffusion transfer image is obtained in reasonable processing times.
The present invention is concerned with photographic processes of this type and with photographic products useful therein for producing multicolor images of improved quality.
It is the primary object of the present invention to provide photographic products and processes of the foregoing description for producing multicolor images exhibiting improved color separation and whiter highlights.
Another object of this invention is to provide photographic products comprising a photosensitive element particularly an integral multilayer photosensitive element having at least one layer of scavenger for silver ion and/or soluble silver complex.
Other objects of the invention will in part be obvious and will in part appear hereinafter.
The invention accordingly comprises the several steps and the relation and order of one or more such steps with respect to each of the others, and the product possessing the features, properties and the relation of elements, which are exemplified in the following detailed disclosure, and the scope of the application which will be indicated in the claims.
For a fuller understanding of the nature and object of the invention, reference should be had to the following detailed description taken in connection with the accompanying drawing.
US Referenced Citations (10)
Divisions (1)
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Number |
Date |
Country |
| Parent |
155123 |
Jun 1971 |
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Continuation in Parts (2)
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Number |
Date |
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| Parent |
465694 |
Apr 1974 |
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| Parent |
317168 |
Dec 1972 |
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Patent Grant
4060417
