GB454794A - Improvements in or relating to photographic developers - Google Patents

Improvements in or relating to photographic developers

Info

Publication number
GB454794A
GB454794A GB1065135A GB1065135A GB454794A GB 454794 A GB454794 A GB 454794A GB 1065135 A GB1065135 A GB 1065135A GB 1065135 A GB1065135 A GB 1065135A GB 454794 A GB454794 A GB 454794A
Authority
GB
United Kingdom
Prior art keywords
grains
pyrocatechin
per
fluid ounce
per cent
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
GB1065135A
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.)
Baird Television Ltd
Original Assignee
Baird Television Ltd
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 Baird Television Ltd filed Critical Baird Television Ltd
Priority to GB1065135A priority Critical patent/GB454794A/en
Priority to FR803568D priority patent/FR803568A/en
Priority to DEF80992D priority patent/DE717512C/en
Publication of GB454794A publication Critical patent/GB454794A/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

Abstract

454,794. Photographic developing- compositions. BANFIELD, A. C., and BAIRD TELEVISION, Ltd., 58, Victoria Street, Westminster. April 5, 1936, No. 10651. Drawings to Specification. [Class 98 (ii)] A photographic developing-composition comprises at least 5 grains of pyrocatechin or of a mixture of pyrocatechin and hydroquinone of which at least one-third is pyrocatechin, at least 10 grains of sodium hydroxide or chemical equivalent, and at least 1 per cent of formaldehyde in every fluid ounce or developer. The developing composition may also include potassium metabisulphite or its chemical equivalent. Solutions containing 25 grains of pyrocatechin and 1 grain of potassium metabisulphite per fluid ounce of water and 50 grains of sodium hydroxide per fluid ounce may be mixed in equal quantities, one fluid ounce of the mixture diluted to 2“ fluid ounces, and 3 per cent of 40 per cent formaldehyde solution added. In a modification a solution containing 20 grains of hydroquinone, 10 grains of pyrocatechin and 1 grain of potassium metabisulphite per fluid ounce is mixed with an equal quantity of a solution containing 50 grains of sodium hydroxide per fluid ounce, the mixture diluted with an equal bulk of water, and 3 per cent of 40 per cent formaldehyde solution added.
GB1065135A 1935-04-05 1935-04-05 Improvements in or relating to photographic developers Expired GB454794A (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
GB1065135A GB454794A (en) 1935-04-05 1935-04-05 Improvements in or relating to photographic developers
FR803568D FR803568A (en) 1935-04-05 1936-03-19 Improvements to photographic developers
DEF80992D DE717512C (en) 1935-04-05 1936-04-07 Fast developer

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB1065135A GB454794A (en) 1935-04-05 1935-04-05 Improvements in or relating to photographic developers

Publications (1)

Publication Number Publication Date
GB454794A true GB454794A (en) 1936-10-05

Family

ID=9971761

Family Applications (1)

Application Number Title Priority Date Filing Date
GB1065135A Expired GB454794A (en) 1935-04-05 1935-04-05 Improvements in or relating to photographic developers

Country Status (3)

Country Link
DE (1) DE717512C (en)
FR (1) FR803568A (en)
GB (1) GB454794A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2506622A (en) * 1944-03-11 1950-05-09 Technicolor Motion Picture Elimination of preservative sulfite from photographic developers prior to use in color development

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2506622A (en) * 1944-03-11 1950-05-09 Technicolor Motion Picture Elimination of preservative sulfite from photographic developers prior to use in color development

Also Published As

Publication number Publication date
DE717512C (en) 1942-02-16
FR803568A (en) 1936-10-03

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