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US 5,633,125 AGranted
Process for extracting halide ions from fixing baths used in photography
AssigneeEastman Kodak Company
InventorDidier J. Martin
Life of this patent
Estimating the term…
Abstract
The invention concerns a process for the selective extraction of the halide ions from photographic fixing solutions. The process consists of bringing the photographic fixing solution into contact with a liquid membrane comprising a solvent and a crown-ether carrier capable of carrying the halide ions from the fixing solution into an aqueous solution which is thus loaded with halides, and is then removed.
Claims8
Process for the selective extraction of the halide ions from photographic fixing solutions, in which
- a) the photographic fixing solution is brought into contact with a liquid membrane comprising a macrocyclic compound in solution in an organic solvent, so that the halide ions are transported from the photographic fixing solution in the liquid membrane, and
- b) the halide ions carried in the liquid membrane are extracted by bringing the membrane into contact with an aqueous solution, separate from the photographic fixing solution characterized in that the macrocyclic compound is a crown-ether compound which comprises at least six oxygen atoms and possibly sulfur or nitrogen atoms, in which two adjacent oxygen, sulfur or nitrogen atoms are separated by an alkylene group of at least two carbon atoms.
Dependencies are inferred from the claim text.