GB466626A - Improvements relating to the manufacture of photographic developers - Google Patents

Improvements relating to the manufacture of photographic developers

Info

Publication number
GB466626A
GB466626A GB785336A GB785336A GB466626A GB 466626 A GB466626 A GB 466626A GB 785336 A GB785336 A GB 785336A GB 785336 A GB785336 A GB 785336A GB 466626 A GB466626 A GB 466626A
Authority
GB
United Kingdom
Prior art keywords
solution
photographic developers
manufacture
pyrocatechin
dihydroxybenzene
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
Application number
GB785336A
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.)
Individual
Original Assignee
Individual
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 Individual filed Critical Individual
Priority to GB785336A priority Critical patent/GB466626A/en
Publication of GB466626A publication Critical patent/GB466626A/en
Expired legal-status Critical Current

Links

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
    • G03C5/00—Photographic processes or agents therefor; Regeneration of such processing agents
    • G03C5/26—Processes using silver-salt-containing photosensitive materials or agents therefor
    • G03C5/29—Development processes or agents therefor
    • G03C5/30—Developers
    • G03C5/3021—Developers with oxydisable hydroxyl or amine groups linked to an aromatic ring

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)

Abstract

Fine grain photographic developers are manufactured by combining p-phenylenediamine with an o-dihydroxybenzene, substituted or not, or a substituted p-dihydroxybenzene, by bringing together aqueous solutions of the components in the presence of a reducing agent of acidic character. In an example, p-phenylenediamine is dissolved in sodium bisulphite solution, treated with decolourizing charcoal, filtered hot, and mixed with a hot solution of pyrocatechin in potassium metabisulphite solution. The pyrocatechin may be replaced by pyrogallol or chloroquinol. Specification 466,625, [Group XX], is referred to.
GB785336A 1936-03-16 1936-03-16 Improvements relating to the manufacture of photographic developers Expired GB466626A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB785336A GB466626A (en) 1936-03-16 1936-03-16 Improvements relating to the manufacture of photographic developers

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB785336A GB466626A (en) 1936-03-16 1936-03-16 Improvements relating to the manufacture of photographic developers

Publications (1)

Publication Number Publication Date
GB466626A true GB466626A (en) 1937-06-01

Family

ID=9841044

Family Applications (1)

Application Number Title Priority Date Filing Date
GB785336A Expired GB466626A (en) 1936-03-16 1936-03-16 Improvements relating to the manufacture of photographic developers

Country Status (1)

Country Link
GB (1) GB466626A (en)

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