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:
Mar. 14, 2017
Filed:
Sep. 11, 2014
Heraeus Quarzglas Gmbh & Co. KG, Hanau, DE;
Stefan Ochs, Gelnhausen, DE;
Heraeus Quarzglas GmbH & Co. KG, Hanau, DE;
Abstract
A method for producing a blank of iron-doped silica glass with high silicic acid content for use as heat protection glass is provided. The method involves: (a) producing an iron-doped SiOsoot body which contains iron in a first oxidation state Feby flame hydrolysis of a silicon-containing and an iron-containing starting substance, (b) drying the soot body to obtain a mean hydroxyl group content of less than 10 ppm by weight, and (c) vitrifying the soot body under a reducing atmosphere that is suitable for at least partially reducing the iron from the first oxidation state Feto a second, lower oxidation state Fe. A blank is obtained having an iron content between 0.1 and 1% by weight which exhibits an internal transmission of at most 40% in the infrared wavelength range and an internal transmission of at least 85% in the visible spectral range.