The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 14, 1978
Filed:
Aug. 12, 1977
Herbert Mollet, Tentlingen, CH;
Ciba-Geigy AG, Basel, CH;
Abstract
A method of processing silver dye bleaching materials is provided wherein a combined aqueous dye and silver bleaching bath is used which contains a strong acid, a water-soluble iodide, a dye bleaching catalyst, a water-soluble oxidant and an antioxidizing agent, wherein the antioxidizing agent is an alkali metal, alkaline earth metal or ammonium bisulphite adduct of an organic carbonyl compound. The dye and silver bleaching can also be carried out in separate baths and then the aqueous dye bleaching bath contains a strong acid, a water-soluble iodide, a dye bleaching catalyst and the antioxidizing agent, which is again said bisulphite adduct. The strongly acid baths which contain as antioxidizing agents the bisulphite adducts are stable over a lengthy period of time, exert a lasting antioxidizing action and are free of offensive odors.