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:
May. 11, 2004
Filed:
Dec. 19, 2001
Applicant:
Inventors:
Gerhard Hoffacker, Aldorf, DE;
Renate Franz, Gelnhausen, DE;
Ramona Reitz, Nidderau, DE;
Richard Walter, Alzenau, DE;
Assignee:
W. C. Heraeus GmbH & Co. KG, , DE;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C25D 3/00 ;
U.S. Cl.
CPC ...
C25D 3/00 ;
Abstract
A method for producing a cyanide-free solution of a gold compound that is suitable for gold electrodeposition baths. The method includes the steps of reacting at least one of a cysteine and a cysteinate with at least one of tetrachloroauric acid and a tetrachloroaurate in a first aqueous medium, separating a resulting precipitate from the first aqueous medium, and dissolving the precipitate in a second aqueous medium with elevation of the pH to 12.0-14.0.