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. 30, 2010
Filed:
Mar. 31, 2006
Dan Goia, Potsdam, NY (US);
Sebastian Fritzsche, Hanau, DE;
Bernd Kempf, Kleinwallstadt, DE;
Peter Braumann, Alzenau, DE;
Thierry Charles Simon Vandevelde, Zolder, BE;
Dan Goia, Potsdam, NY (US);
Sebastian Fritzsche, Hanau, DE;
Bernd Kempf, Kleinwallstadt, DE;
Peter Braumann, Alzenau, DE;
Thierry Charles Simon Vandevelde, Zolder, BE;
Umicore, S.A., Brussels, BE;
Abstract
The invention is directed to a process for manufacture of fine precious metal containing particles, specifically silver-based particles and silver-based contact materials via an intermediate silver(+1)-oxide species. The process comprises in a first step the formation of a thermally instable silver (+1)-oxide species by adding a base to an aqueous silver salt solution comprising an organic dispersing agent. Due to the presence of the organic dispersing agent, the resulting silver (+1)-oxide species is thermally instable, thus the species is decomposing to metallic silver at temperature lower than 100° C. The process optionally may comprise the addition of a powdered compound selected from the group of inorganic oxides, metals, and carbon-based compounds. Furthermore the process may contain additional separating and drying steps. The process is versatile, cost efficient and environmentally friendly and is used for the manufacture of silver-based particles and electrical contact materials. Silver nanoparticles made according to the process are characterized by a narrow particle size distribution. Electrical contact materials manufactured according to the process reveal improved contact welding properties.