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:
Apr. 15, 2014
Filed:
Dec. 10, 2009
Georg Schroll, Nuβdorf, DE;
Georg Schroll, Nuβdorf, DE;
Alzchem Trostberg GmbH, Trostberg, DE;
Abstract
A method for producing high-purity silicon nitride in two steps is described, wherein a) high-purity silicon is reacted with nitrogen in a rotary tubular furnace comprising a first temperature zone of 1,150 to 1,250° C. and at least one other temperature zone of 1,250 to 1,350° C. in the presence of a gas mixture comprising argon and hydrogen, said reaction proceeding up to a nitrogen content of 10 to 30 wt % and b) allowing the partially nitrogen-containing product from step a) to react in a chamber or settling furnace in a quiescent bed at 1,100 to 1,450° C. with a mixture of nitrogen, argon and optionally hydrogen up to the completion of nitrogen uptake. It is possible, utilizing the method according to the invention, to produce high-purity silicon nitride with a purity of >99.9 in a technically simple manner, wherein no further purification steps, such as leaching with inorganic acids, are required.