US2984565A - Photographic process and composition - Google Patents

Photographic process and composition Download PDF

Info

Publication number
US2984565A
US2984565A US16100A US1610060A US2984565A US 2984565 A US2984565 A US 2984565A US 16100 A US16100 A US 16100A US 1610060 A US1610060 A US 1610060A US 2984565 A US2984565 A US 2984565A
Authority
US
United States
Prior art keywords
silver
silver halide
print
cysteine
composition
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US16100A
Inventor
Meroe M Morse
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Polaroid Corp
Original Assignee
Polaroid Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Polaroid Corp filed Critical Polaroid Corp
Priority to US16100A priority Critical patent/US2984565A/en
Priority claimed from GB20692/60A external-priority patent/GB883935A/en
Application granted granted Critical
Publication of US2984565A publication Critical patent/US2984565A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03C—PHOTOSENSITIVE MATERIALS FOR PHOTOGRAPHIC PURPOSES; PHOTOGRAPHIC PROCESSES, e.g. CINE, X-RAY, COLOUR, STEREO-PHOTOGRAPHIC PROCESSES; AUXILIARY PROCESSES IN PHOTOGRAPHY
    • G03C8/00—Diffusion transfer processes or agents therefor; Photosensitive materials for such processes
    • G03C8/24—Photosensitive materials characterised by the image-receiving section
    • G03C8/243—Toners for the silver image
    • 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
    • Y10S430/166—Toner containing

Definitions

  • the present invention relates to photography and, more particularly, to the production of photographic prints by silver transfer.
  • Silver transfer techniques generally involve subjecting a silver halide latent image to developing and dissolving reagents in the presence of a silver-receptive environment where a visible silver print is formed.
  • a fluid such as an alkaline aqueous solution of a silver halide developing agent and a silver solvent, is applied to a pair of strata, for example a photoexposed silver halide stratum and a silver-receptive stratum that are superposed. Thereafter, the strata are maintained in superposed relation for a predetermined processing period during which the reagents develop exposed silver halide to silver and react with unreduced silver halide to form a soluble silver complex that is reduced to silver in the print-receptive stratum to form a positive print.
  • the present invention contemplates improving silver transfer techniques with the aid of an additive, initially disposed, for example, either in the fluid or on one of the sheets, that serves to enhance the character of the resulting print.
  • the primary object of the present invention is to enhance the blackness of a silver transfer print with the aid of cysteine, otherwise known as alpha-amino-betathiol-propionic acid.
  • the invention accordingly comprises the process involving the several steps and the relation and order of one or more of such steps with respect to each of the others and the composition possessing the features, prop erties and the relation of components which are exemplified in the following detailed disclosure, and the scope of the application of which will be indicated in the claims.
  • Figure 1 is an exaggerated cross-sectional view of photographic materials undergoing a preferred process embodying the present invention.
  • Fig. 2 is an exaggerated cross-sectional view of the print produced by the process of Fig. 1.
  • Fig. 1 shows a silver halide processing fluid 10 spread in a uniformly thin layer between the adjacent superposed surfaces of a silver halide photosensitive sheet 12 and a silver print-receptive sheet 14.
  • Such spreading for example, is accomplished by advancing the sheets, to-. gether with the fluid, between a pair of pressure-applying rollers.
  • the liquid is sufficiently viscous to be readily controlled as it is spread, in accordance with the teachings of US. Patent No. 2,543,181, issued to Edwin H. Land on February 27, 1951.
  • cysteine represented by the formula:
  • cysteine in viscous alkaline solution with a silver halide developing agent such as hydroquinone, a silver halide solvent such as sodium thiosulfate and a thickener such as a watersoluble polymer or gum or an insoluble emulsifiable oil.
  • a silver halide developing agent such as hydroquinone
  • a silver halide solvent such as sodium thiosulfate
  • a thickener such as a watersoluble polymer or gum or an insoluble emulsifiable oil.
  • the cysteine is present in a concentration elfective to render the resulting silver transfer image substantially more neutral in tone, e.g., blue-black, as compared with the image which would be obtained in its absence.
  • the cysteine is present in a concentration, by weight of said solution, of about 0.001 to 0.60%.
  • the photosensitive sheet includes a gelatino silver halide stratum 16 on a suitable support 18 and the print-receptive sheet includes a silver-receptive stratum 20 on a suitable support 22.
  • the reagents therein form a negative'print in silver halide stratum 16 by-reducing silver halide to silver and react with unreduced silver halide to form a silver complex which difiuses into the layer of processing fluid to silver-receptive stratum 20 where it is reduced to silver to form a positive print.
  • the presence of the cysteine is responsible for a considerably more neutral tone in the resulting print than would exist in its absence.
  • silver halide stratum 16 and silver-receptive stratum 20 are maintained in superposed relation with processing fluid 10 therebetween for a period of approximately from 40 to 120 seconds in duration. At the end of this period, silver-receptive stratum 20 and layer of solution 10 are stripped from silver halide stratum 16 to display a positive print of substantially richer and blacker tone than would have been obtained in the absence of cysteine. The presence of cysteine also appreciably increases the effective speed of the process.
  • the proportions of the ingredients of processing fluid 10 may be varied within wide limits. However, where the processing period is as specified, within the range of from 40 to 120 seconds in accordance with the now conventional duration of silver diffusion transfer processing periods, practical results are achieved where, by total weight of the fluid, 'the developing agent ranges from 1 to 8%, the silver halide solvent from 0.3 to 10%, and the thickener is in suflicient concentration. to impart to the fluid a viscosity of from to 200,000 centipoises at a temperature of 20 C. Practical results: are achieved in the process of the aboveexample when the cysteine 3 ranges, by total weight of the fluid, from 0.001 to 0.40% of. the fluid.
  • the present invention may be applied to a variety of 'silver transfer processes other than the one specifically referred to above.
  • the fluid may be spread either between the adjacent faces or on one of the remote faces of the superposed silver halide silver-receptive strata before or after photoexposure.
  • the fluid itself may contain a silver precipitating agent in the presence of which print formation occurs, so that the solidified layer of said fluid contains the desired silver transfer image, in accordance with the principles of Patent No. 2,662,822 issued to Edwin H. Land on December 15, 1953, e.g., a composition like that of Example 1 of said patent.
  • a composition like that of Example 1 of said patent in accordance with the principles of Patent No. 2,662,822 issued to Edwin H. Land on December 15, 1953, e.g., a composition like that of Example 1 of said patent.
  • the additive of the present invention is especially useful in the processes of the latter patent to render more blue.
  • the additive of the present invention is preferably present in proportions varying from 0.002 to 0.60% of the composition by weight. It may also be usefully employed in processes which provide a support with a photosensitive coating by application of a photosensitive material in accordance with the principles of United States Patent No. 2,846,309 granted August 5, 1958 to Edwin H. Land. Before photoexposure, such a process may initiate development to provide a dynamic photosensitive stratum in which a latent image later formed develops spontaneously in accordance with the principles of United States application Serial No. 498,672, filed April 1, 1955 in the name of Edwin H. Land.
  • the two sheets may be stripped apart to uncover the resulting print or may be retained in superposed relation, when the maximum density of the negative is small compared to the maximum density of the positive print, in accordance with the teachings of United States Patent No. 2,861,885, granted November 25, 1958 to Edwin H. Land.
  • the photographically active materials including the cysteine, may be carried at a variety of locations, e.g., in the container or on one of the sheets.
  • the photosensitive emulsion may be coated over the silver-receptive stratum, with the processing liquid being applied to the surface of the emulsion. After the desired transfer has been effected, the emulsion layer is stripped off.
  • the present invention thus is based upon the discovery of the unique properties of cysteine in relation to silver diffusion transfer processes and compositions useful therein.
  • a photographic composition comprising an alkaline aqueous solution of a silver halide solvent fixer, a silver halide developing agent and cysteine, said cysteine ranging from about 0.001 to 0.60%, said developer ranging from about 1 to 8% and said silver halide solvent fixer ranging from about 0.3 to 10%, by total weight of said composition.
  • composition of claim 1' wherein said composition is a fluid possessing a viscosity of from 100 to 200,000 centipoises at a temperature of 20 C.
  • a photographic process for producing a visible print comprising the steps of applying a processing liquid to an exposed silver halide emulsion and efiecting development of said exposed silver halide by a silver halide developing agent, reacting a silver halide solvent with at least a portion of the unexposed silver halide to form a soluble silver complex, and transferring said soluble silver complex to a silver-receptive stratum in superposed relationship with said silver halide emulsion, said silver-receptive stratum containing a silver precipitating agent whereby said transferred silver complex is precipitated to form said visible print, said process being efiected in the presence of cysteine in a concentration, by total weight of said processing liquid, of about 0.001 to 0.60%.

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Silver Salt Photography Or Processing Solution Therefor (AREA)

Description

Silvzr Halide S+ru+um May 16, 1961 M. M. MORSE 7 2,984,565
' PHOTOGRAPHIC PROCESS AND cowosmon Filed March 18, 1960 Silver Halide Developer "N and Solvcn'f, and Cys+eine Silver Recepi'ive Shahim if Aqueous So|u+ion of Supporl' FIG. I
Silv cr Tr unsfer Reversal Prin+ Con'laining Cys+eine }v\/ I /A .4 Suppori -22 ATTORNEYS United States Patent PHOTOGRAPHIC PROCESS AND COMPOSITION Meme M. Morse, Boston, Mass asslgnor to Polaroid Corporation, Cambridge, Mass, a corporation of Delawere Filed Mar. 18, 1960, Ser. No. 16,100
7 Claim. (Cl. 96-29) The present invention relates to photography and, more particularly, to the production of photographic prints by silver transfer.
Silver transfer techniques generally involve subjecting a silver halide latent image to developing and dissolving reagents in the presence of a silver-receptive environment where a visible silver print is formed. For example, a fluid, such as an alkaline aqueous solution of a silver halide developing agent and a silver solvent, is applied to a pair of strata, for example a photoexposed silver halide stratum and a silver-receptive stratum that are superposed. Thereafter, the strata are maintained in superposed relation for a predetermined processing period during which the reagents develop exposed silver halide to silver and react with unreduced silver halide to form a soluble silver complex that is reduced to silver in the print-receptive stratum to form a positive print. The present invention contemplates improving silver transfer techniques with the aid of an additive, initially disposed, for example, either in the fluid or on one of the sheets, that serves to enhance the character of the resulting print.
The primary object of the present invention is to enhance the blackness of a silver transfer print with the aid of cysteine, otherwise known as alpha-amino-betathiol-propionic acid.
Other objects of the invention will in part be obvious and will in part appear hereinafter.
The invention accordingly comprises the process involving the several steps and the relation and order of one or more of such steps with respect to each of the others and the composition possessing the features, prop erties and the relation of components which are exemplified in the following detailed disclosure, and the scope of the application of which will be indicated in the claims.
For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description taken in connection with the accompanying drawing wherein:
Figure 1 is an exaggerated cross-sectional view of photographic materials undergoing a preferred process embodying the present invention; and
Fig. 2 is an exaggerated cross-sectional view of the print produced by the process of Fig. 1.
Generally, Fig. 1 shows a silver halide processing fluid 10 spread in a uniformly thin layer between the adjacent superposed surfaces of a silver halide photosensitive sheet 12 and a silver print-receptive sheet 14. Such spreading, for example, is accomplished by advancing the sheets, to-. gether with the fluid, between a pair of pressure-applying rollers. Preferably, the liquid is sufficiently viscous to be readily controlled as it is spread, in accordance with the teachings of US. Patent No. 2,543,181, issued to Edwin H. Land on February 27, 1951. In accordance cysteine, represented by the formula:
0 IYTH:
H0--("J-CHCH:8H
in viscous alkaline solution with a silver halide developing agent such as hydroquinone, a silver halide solvent such as sodium thiosulfate and a thickener such as a watersoluble polymer or gum or an insoluble emulsifiable oil. The cysteine is present in a concentration elfective to render the resulting silver transfer image substantially more neutral in tone, e.g., blue-black, as compared with the image which would be obtained in its absence. In a preferred embodiment, the cysteine is present in a concentration, by weight of said solution, of about 0.001 to 0.60%. The photosensitive sheet includes a gelatino silver halide stratum 16 on a suitable support 18 and the print-receptive sheet includes a silver-receptive stratum 20 on a suitable support 22. Within a predetermined period after solution 10 is spread, the reagents therein form a negative'print in silver halide stratum 16 by-reducing silver halide to silver and react with unreduced silver halide to form a silver complex which difiuses into the layer of processing fluid to silver-receptive stratum 20 where it is reduced to silver to form a positive print. The presence of the cysteine is responsible for a considerably more neutral tone in the resulting print than would exist in its absence.
' Example Grams Hydroquinone 52.0 Sodium thiosulfate 14.5 Cysteine 5.2 Sodium hydroxide 54.6 Sodium sulfite 78.0 Sodium carboxymethyl cellulose 93.0 Water 1860.0
Here, silver halide stratum 16 and silver-receptive stratum 20 are maintained in superposed relation with processing fluid 10 therebetween for a period of approximately from 40 to 120 seconds in duration. At the end of this period, silver-receptive stratum 20 and layer of solution 10 are stripped from silver halide stratum 16 to display a positive print of substantially richer and blacker tone than would have been obtained in the absence of cysteine. The presence of cysteine also appreciably increases the effective speed of the process.
The proportions of the ingredients of processing fluid 10 may be varied within wide limits. However, where the processing period is as specified, within the range of from 40 to 120 seconds in accordance with the now conventional duration of silver diffusion transfer processing periods, practical results are achieved where, by total weight of the fluid, 'the developing agent ranges from 1 to 8%, the silver halide solvent from 0.3 to 10%, and the thickener is in suflicient concentration. to impart to the fluid a viscosity of from to 200,000 centipoises at a temperature of 20 C. Practical results: are achieved in the process of the aboveexample when the cysteine 3 ranges, by total weight of the fluid, from 0.001 to 0.40% of. the fluid.
The present invention may be applied to a variety of 'silver transfer processes other than the one specifically referred to above. The fluid may be spread either between the adjacent faces or on one of the remote faces of the superposed silver halide silver-receptive strata before or after photoexposure. The fluid itself may contain a silver precipitating agent in the presence of which print formation occurs, so that the solidified layer of said fluid contains the desired silver transfer image, in accordance with the principles of Patent No. 2,662,822 issued to Edwin H. Land on December 15, 1953, e.g., a composition like that of Example 1 of said patent. In fact,
- the additive of the present invention is especially useful in the processes of the latter patent to render more blue.
black the sepia images which are normally obtainedfrom using the compositions of the aforesaid patent. When used in these compositions, the additive of the present invention is preferably present in proportions varying from 0.002 to 0.60% of the composition by weight. It may also be usefully employed in processes which provide a support with a photosensitive coating by application of a photosensitive material in accordance with the principles of United States Patent No. 2,846,309 granted August 5, 1958 to Edwin H. Land. Before photoexposure, such a process may initiate development to provide a dynamic photosensitive stratum in which a latent image later formed develops spontaneously in accordance with the principles of United States application Serial No. 498,672, filed April 1, 1955 in the name of Edwin H. Land. The two sheets may be stripped apart to uncover the resulting print or may be retained in superposed relation, when the maximum density of the negative is small compared to the maximum density of the positive print, in accordance with the teachings of United States Patent No. 2,861,885, granted November 25, 1958 to Edwin H. Land. When the various materials are associated in the form of a film -unit having a pair of sheets and a container whose contents are to be spread between the sheets, the photographically active materials, including the cysteine, may be carried at a variety of locations, e.g., in the container or on one of the sheets. The photosensitive emulsion may be coated over the silver-receptive stratum, with the processing liquid being applied to the surface of the emulsion. After the desired transfer has been effected, the emulsion layer is stripped off.
The present invention thus is based upon the discovery of the unique properties of cysteine in relation to silver diffusion transfer processes and compositions useful therein.
This application is a continuation in part of my 00- pending application, Serial No. 619,604, filed October 31, 1956 (now abandoned).
and composition without departing'from the scope of the invention herein involved, it is intended that all matter contained in the above description or shown in the accompanying drawing shall be interpreted as illustrative and not in a limiting sense.
What is claimed is:
l. A photographic composition comprising an alkaline aqueous solution of a silver halide solvent fixer, a silver halide developing agent and cysteine, said cysteine ranging from about 0.001 to 0.60%, said developer ranging from about 1 to 8% and said silver halide solvent fixer ranging from about 0.3 to 10%, by total weight of said composition.
2. The photographic composition of claim 1', wherein said composition is a fluid possessing a viscosity of from 100 to 200,000 centipoises at a temperature of 20 C.
3. The photographic composition of claim 1, wherein said solution includes a silver precipitating agent.
4. A photographic process for producing a visible print, said process comprising the steps of applying a processing liquid to an exposed silver halide emulsion and efiecting development of said exposed silver halide by a silver halide developing agent, reacting a silver halide solvent with at least a portion of the unexposed silver halide to form a soluble silver complex, and transferring said soluble silver complex to a silver-receptive stratum in superposed relationship with said silver halide emulsion, said silver-receptive stratum containing a silver precipitating agent whereby said transferred silver complex is precipitated to form said visible print, said process being efiected in the presence of cysteine in a concentration, by total weight of said processing liquid, of about 0.001 to 0.60%.
5. The photographic process of claim 4, wherein said silver halide developing agent ranges from about 1 to 8%, and said silver halide solvent ranges from about 0.3 to 10%, by .total weight of said liquid.
6. The photographic process of claim 5, wherein said liquid contains a thickener in sufiicient quantity to impart a viscosity of from 100 to 200,000 centipoises at a tem- .perature of 20 C.
7. The photographic process of claim 4, wherein said silver precipitating agent is contained in said processing liquid, and said visible print is contained in a solidified layer of said processing liquid.
References Cited in the file of this patent UNITED STATES PATENTS Urbach Sept. 14, 1948 Land Apr. 3, 156
OTHER REFERENCES Chem. Abstracts, 41, 20l6d (1947).
I changes maybemadeinthe abovepm Chem. Abstracts, 33, 2498 (1939).

Claims (1)

  1. 4. A PHOTOGRAPHIC PROCESS FOR PRODUCING A VISIBLE PRINT, SAID PROCESS COMPRISING THE STEPS OF APPLYING A PROCESSING LIQUID TO AN EXPOSED SILVER HALIDE EMULSION AND EFFECTING DEVELOPMENT OF SAID EXPOSED SILVER HALIDE BY A SILVER HALIDE DEVELOPING AGENT, REACTING A SILVER HALIDE SOLVENT WITH AT LEAST A PORTION OF THE UNEXPOSED SILVER HALIDE TO FORM A SOLUBLE SILVER COMPLEX, AND TRANSFERRING SAID SOLUBLE SILVER COMPLEX TO A SILVER-RECEPTIVE STRATUM IN SUPERPOSED RELATIONSHIP WITH SAID SILVER HALIDE EMULSION, SAID SILVER-RECEPTIVE STRATUM CONTAINING A SILVER PRECIPITATING AGENT WHEREBY SAID TRANSFERRED SILVER COMPLEX IS PRECIPITATED TO FORM SAID VISIBLE PRINT, SAID PROCESS BEING EFFECTED IN THE PRESENCE OF CYSTEINE IN A CONCENTRATION, BY TOTAL WEIGHT OF SAID PROCESSING LIQUID, OF ABOUT 0.001 TO 0.60%.
US16100A 1960-03-18 1960-03-18 Photographic process and composition Expired - Lifetime US2984565A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US16100A US2984565A (en) 1960-03-18 1960-03-18 Photographic process and composition

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US16100A US2984565A (en) 1960-03-18 1960-03-18 Photographic process and composition
GB20692/60A GB883935A (en) 1960-06-13 1960-06-13 Photographic process and composition

Publications (1)

Publication Number Publication Date
US2984565A true US2984565A (en) 1961-05-16

Family

ID=26254832

Family Applications (1)

Application Number Title Priority Date Filing Date
US16100A Expired - Lifetime US2984565A (en) 1960-03-18 1960-03-18 Photographic process and composition

Country Status (1)

Country Link
US (1) US2984565A (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3232759A (en) * 1962-09-13 1966-02-01 Eastman Kodak Co Diffusion transfer process employing tone modifiers
US3343958A (en) * 1965-04-09 1967-09-26 Polaroid Corp Monobath containing cysteine-nitrogenous base combination
US3396018A (en) * 1963-05-17 1968-08-06 Eastman Kodak Co Diffusion transfer system
US3861919A (en) * 1970-03-30 1975-01-21 Itek Corp A photoconductor process using a copy medium sensitized with an amine

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2449153A (en) * 1944-04-03 1948-09-14 Urbach Franz Photographic silver bromide emulsion sensitized with cysteine
US2740715A (en) * 1952-10-10 1956-04-03 Polaroid Corp Photographic processes for producing prints by transfer and products useful in connection therewith

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2449153A (en) * 1944-04-03 1948-09-14 Urbach Franz Photographic silver bromide emulsion sensitized with cysteine
US2740715A (en) * 1952-10-10 1956-04-03 Polaroid Corp Photographic processes for producing prints by transfer and products useful in connection therewith

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3232759A (en) * 1962-09-13 1966-02-01 Eastman Kodak Co Diffusion transfer process employing tone modifiers
US3396018A (en) * 1963-05-17 1968-08-06 Eastman Kodak Co Diffusion transfer system
US3343958A (en) * 1965-04-09 1967-09-26 Polaroid Corp Monobath containing cysteine-nitrogenous base combination
US3861919A (en) * 1970-03-30 1975-01-21 Itek Corp A photoconductor process using a copy medium sensitized with an amine

Similar Documents

Publication Publication Date Title
US2635048A (en) Photographic transfer product and process
US3020155A (en) Photographic diffusion transfer process
US2759825A (en) Photographic image transfer process
US2698244A (en) Photographic transfer process utilizing a primary color developer for producing a colored photographic transfer image
US2977226A (en) Photographic process, product and apparatus
US2603565A (en) Photographic film forming image transfer composition
US2704721A (en) Photographic diffusion transfer reversal processes
US3087816A (en) Photographic diffusion transfer process
US2774667A (en) Photographic silver halide transfer process
US3607269A (en) Image-receiving elements and photographic processes employing same
US2984565A (en) Photographic process and composition
US3769014A (en) Beta-disulfone silver halide solubilizing agents
US3077400A (en) Color diffusion transfer using gelatinsilver halide emulsions containing cellulose ethers
US3772025A (en) Diffusion transfer receiving sheets
US2962377A (en) Photographic processes and compositions useful therein
US3260600A (en) Photographic image-receiving material
US2584029A (en) Photographic silver transfer product and process, including a lead salt
US3549364A (en) Photographic processes and compositions
US2698238A (en) Photographic product and process
US3698900A (en) Diffusion transfer process utilizing 2-mercapto imidazoles
US3335005A (en) Silver complex diffusion transfer process
US3406064A (en) Diffusion transfer with 4-methylphenylhydroquinone in the emulsion and n,n-diethylhydroxylamine in the processing fluid
US3565619A (en) Photographic image transfer process utilizing imidazolidine-2-thione
US4530898A (en) Photographic products and processes providing a negative image
US4047952A (en) Imagewise soluble silver salt intensification of diffusion transfer silver images