US530965A - Albrecht schmidt - Google Patents

Albrecht schmidt Download PDF

Info

Publication number
US530965A
US530965A US530965DA US530965A US 530965 A US530965 A US 530965A US 530965D A US530965D A US 530965DA US 530965 A US530965 A US 530965A
Authority
US
United States
Prior art keywords
persulphate
fixing agent
sodium
albrecht
schmidt
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
Publication date
Application granted granted Critical
Publication of US530965A publication Critical patent/US530965A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Classifications

    • GPHYSICS
    • G03PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03CPHOTOSENSITIVE MATERIALS FOR PHOTOGRAPHIC PURPOSES; PHOTOGRAPHIC PROCESSES, e.g. CINE, X-RAY, COLOUR, STEREO-PHOTOGRAPHIC PROCESSES; AUXILIARY PROCESSES IN PHOTOGRAPHY
    • G03C5/00Photographic processes or agents therefor; Regeneration of such processing agents
    • G03C5/26Processes using silver-salt-containing photosensitive materials or agents therefor
    • G03C5/268Processing baths not provided for elsewhere, e.g. pre-treatment, stop, intermediate or rinse baths

Definitions

  • ALBRECHT SCHMIDT OF BERLIN, GERMANY.
  • My invention relates to the removal of the fixing agent-for instance of the hyposul phite of sodium-by treating the fixed pictures with persulphates.
  • the solution must not be too much concentrated in order to avoid an oxidation of the silver.
  • the solutions may also be made slightly alkaline. The efiect of slightly acid solutions is not so favorable.

Landscapes

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

Description

UNITED STATES PATENT OFFICE.
ALBRECHT SCHMIDT, OF BERLIN, GERMANY.
HYPOFELIMINATOR.
SPECIFICATION forming part of Letters Patent No. 530,965, dated December 18, 1894. Arrliwtion fileflJuly .189 Serial No. 516,995. (No specimens.)
To all whom it may concern:
Be it known that I, ALBRECHT SCHMIDT, a subject of the King of Prussia, residing at 170 and 171 Mullerstrasse, Berlin, Prussia, Germany, have invented certain new and useful Improvements in and Relating to the Removal of the Fixing Agent from Photo graphic Pictures; and I do hereby declare the following to be afull, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.
My invention relates to the removal of the fixing agent-for instance of the hyposul phite of sodium-by treating the fixed pictures with persulphates.
Complaints are constantly heard of incomplete elutriation of the sodium fixing agent from photographic pictures and consequent discoloration of the photographs. Chloride of lime and eau de javelle which have been repeatedly recommended for destroying the last traces of the fixing agent, hyposulphite of sodium, and consequently shortening the elutriation process, have only been attended with slight success on account of their extremely inconstant composition. They have also other drawbacks.
Now I have found that the salts of persulphuric acid are excellently adapted for rendering an excess of hyposulphite harmless by oxidation. After the photograph has been fixed, the plate or paper is immersed in a dilute solutionof persulphate of potassium or of persulphate of ammonium or of persulphate of sodium. The formula of such a persulphate is represented by B 8 0 In this formula R stands for the radical, which may be potassium, sodium or ammonium. While otherwise it is necessary to wash for hours before the wash water no longer gives a yellow'precipitate with silver nitrate, the employment 0f persulphate effects the removal of all fixing agent in a far shorter time, and the subsequent discoloration of the plate is prevented.
Properly a one percent. solution of persulphate may be employed.
The solution must not be too much concentrated in order to avoid an oxidation of the silver. The solutions may also be made slightly alkaline. The efiect of slightly acid solutions is not so favorable.
Having thus described my invention and in what manner it is to be carried out, what I claim as new, and desire to secure by Letters Patent, is-
In the art of photography the improvement which consists in removing the fixing agent from photographic pictures by treating them
US530965D Albrecht schmidt Expired - Lifetime US530965A (en)

Publications (1)

Publication Number Publication Date
US530965A true US530965A (en) 1894-12-18

Family

ID=2599744

Family Applications (1)

Application Number Title Priority Date Filing Date
US530965D Expired - Lifetime US530965A (en) Albrecht schmidt

Country Status (1)

Country Link
US (1) US530965A (en)

Similar Documents

Publication Publication Date Title
DE1185925B (en) Process for the production of printing forms
DE2113801A1 (en) Bleach-fix bath
US2440110A (en) Stabilized silver halide emulsions
EP0020397A1 (en) Photographic bleach compositions and methods of photographic processing.
DE1012176B (en) Process for the production of images according to the silver salt diffusion process and means for carrying out the process
GB390037A (en) An improvement in photographic emulsions
US530965A (en) Albrecht schmidt
DE934512C (en) Process for simultaneously bleaching and fixing a color photographic image
US2656273A (en) Photographic developers containing diamino-propanol tetracetic acid
US3960565A (en) Silver bleaching solutions
US3806345A (en) Hydroxylamine photographic developer
US2384593A (en) Antifoggant
US4033772A (en) Amphoteric maleic anhydride copolymers and photographic emulsions employing the same
US2378265A (en) Color photography
US2388816A (en) Photographic developer
US2221163A (en) Recovery of silver from spent photographic solutions
DE1212839B (en) Process for the preparation of photographic silver halide emulsions by the flocculation method using copolymers as flocculants
US1361352A (en) Process of desensitizing photo-sensitive silver compounds
UST910002I4 (en) Defensive publication
US3129097A (en) Manufacture of photographic gelatin relief images
US2674533A (en) Compositions and processes for the development of silver halide elements
DE954391C (en) Halogen silver layers containing developer substances
US3578453A (en) Color photographic processing with water soluble amines and salts thereof
US2678883A (en) Preparation of photographic emulsions
SU58982A1 (en) The method of dissolving silver sulfide